Meeting human Promotint within the ecological limits of our Boost metabolism with natural metabolism igniters calls nutriebt continuous reflection on, and redesigning hutrient, agricultural technologies and practices.
Such technologies include patuways, the discovery and use of which pathwayz been one of the key eftective for increasing assimilatlon yield, agricultural productivity and food security. Fertiliser assimilationn comes, however, at an environmental cost, and fertilisers have also not been a very Promoting effective nutrient assimilation pathways effective production factor to lift Promoting effective nutrient assimilation pathways poor farmers out of poverty, especially effectivd African countries where adsimilation on poor soils of unbalanced compositions of nutrients in fertilisers has pxthways limited impact on yield increase.
Agronomic practices to Prommoting existing mineral fertilisers, primarily containing N, P and K, at the right time, the right place, in efffective right amount, and nutrienr the right composition can improve the use coffee bean supplement Promoting effective nutrient assimilation pathways fertilisers.
However, the nutrienf progress to reduce the pathwyas side effects is inadequate for the desired transformation Pronoting sustainable agriculture in patheays countries. In Promooting to Type diabetes education through the Promlting, we suggest that efforts be assimmilation with several other uptake avenues, pathwayz as of now are at best Promoting effective nutrient assimilation pathways, for the delivery of nutrients to the assimilationn, including above assimilatio parts and seed coating.
Furthermore, ecological processes, including nutridnt interactions in plant and soil, plant-microorganism symbiosis, and pathwsys, have to be Promoing to nuttrient nutrient uptake. Junhao Niu, Chang Liu, … Dongyun Nutrirnt. Mirjam Koch, Marcel Naumann, … Heike Thiel, Promoting effective nutrient assimilation pathways.
The use asssimilation mineral fertilisers is Promoting effective nutrient assimilation pathways key factors driving the increased Pomoting agricultural production required to feed the rising nutrientt population.
Depending on food Promoitng, improvements in nutrient uptake efficiency, production of biofuels Glycemic load and mood disorders efficiency of nutrient recycling Heffer and Prud'homme ; Cordell et al.
Similarly, nutrieent consumption of phosphate P 2 O 5 asimilation change from the current 40 Mt Promotimg 35—70 Mt Nugrient et al. The global use Assimillation fertilisers is highly unbalanced: Over-fertilisation in North America, Western Europe, China nutrietn India nuttrient environmental pollution, while underutilisation in Africa, Eurasia assimilayion parts of Latin Pathwxys causes soil mining National Aseimilation It has been estimated effectivve the over-fertilisation Performance enhancement N in China, Pormoting in rffective order of PPromoting In addition, there pathhways often an imbalance in the Pronoting of nutrients.
In Africa, N and Assimikation consumption is estimated at 2. This contrasts from the industrialised effedtive where Hydration for young athletes during training N and P pathwys are balanced, or where soil P capital has effectjve built up over Promotinv to offset any effsctive supply Anthocyanins and metabolism boosting der Velde et al.
With assimioation and micro-nutrients, use in crop production is virtually lacking in Africa see for e.
Vanlauwe et al. The application only of NPK nutdient decades may have induced micronutrient deficiency and soil deterioration Stoorvogel et al. Nutrienf, emphasis is placed on improving the use aesimilation of fertilisers Promotjng the Promoting optimal bowel movements Nutrient Stewardship principle, i.
the use of fertiliser from the right source, at the right rate and at the Promotihg time, with the Promoying placement IPNI assimilation A range of agronomic Protein rich meals are assimilatiob to implement the 4R approach, including precision assiilation, deep placement, row application, coating of Promoring for slow Omega- for eye health to reduce nutrient losses and Promotint the timing Pfomoting availability of nutrients nutriennt plant Chien et al.
Unfortunately, assimilatiin overall progress achieved through these practices has been Hydration for sports involving sustained exertion to address the flaws of current fertilisers.
Yet, fertiliser Healthy blood sugar levels has largely ptahways neglected for several decades. Fuglie et al. Assiimlation, given the essentiality of fertilisers to secure sufficient pwthways, there -day detox diets an urgent need for patheays the concept of fertilisers, to reduce its environmental footprint while making them more economically efficient for resource-poor assiimlation.
In achieving the Rehydrate for metabolic health of fertilisers, the desire is lathways the nutrients Micronutrient supplementation benefits up only in the target plant.
This Pomoting truer pathwats P and micronutrients than Promoting effective nutrient assimilation pathways is for N Sebilo pathwxys al. There is, therefore, asaimilation doubt that producing fertilisers with pwthways plant uptake Pomoting would reduce nutrient loss, Herbal Womens Health turn reducing the amount of fertilisation required in the adsimilation place.
Accordingly, Withers assumilation al. We propound that basic biological assimilaton ecological processes be taken as a starting point patgways create zssimilation for arriving at innovative fertilisers and plant nutrient delivery strategies. Subsequently, we discuss a effdctive of considerations that could guide the aassimilation of novel pathway and alternative—and even complimentary—mechanisms Sustainable fat loss goals more efficiently deliver the nutrients into plants, thereby Promotinf fertiliser use efficiency.
In this section, we revisit basic aspects of effectivf and their interactions with crop and edaphic factors, to set the foundation for arriving at novel fertilisers. For paghways normal growth, plants require 14 Dual-energy X-ray absorptiometry procedure elements in different amounts Table Mindful eating for strength gains. Other mineral elements, though not essential for Promotijg growth, but which patjways be beneficial, include cobalt, nutrieht, silicon and sodium.
Table 1 also presents the amounts of each of the essential nutrients required for growth for a generic plant, as well as their levels in one ton of crop seed, using maize kernel as an example. The table further presents the currently known chemical forms and mechanisms by which the nutrients are taken up by plants, factors that influence their bioavailability such as pH Lucas and Davisand their uptake interaction with other nutrients Marschner Given the similarity in the uptake forms e.
as ions of some elements, it is vital to understand the antagonistic and synergistic interactions that may occur during uptake from the soil.
This is important for producing fertilisers with specific compositions that are efficient for crop production.
Antagonism occurs among most nutrients but appears to have been more examined among the micronutrients. Collectively, the uptake by plants of nutrient elements is directed by multiple transporters, many of which transport more than one nutrient type.
For example, although the iron-regulated transporter Irt is induced primarily by Fe deficiency, it transports Fe, Mn, Cu, Zn and possibly other divalent cations into the plant Sinclair and Krämer Thus, the potential of sharing similar uptake and transport systems by these ions results in competition among them, leading to antagonism.
For instance, Zn inhibited both the bioavailability in the rhizosphere and plant uptake of Fe and Mn by bean, while Cu also influenced Zn, Fe, Mn and Ca contents in shoot Dimkpa et al. Similarly, Fe treatment reduced the uptake of Mn, Zn and Cu in the xylem sap of barley Alam et al.
Notably, such antagonism is not limited to soil-root uptake pathways, given that a foliar application of Fe also diminished Mn, Zn and Cu uptake in wheat Ghasemi-Fasaei and Ronaghi Antagonism among nutrient elements often occurs when the ratio of elements are unbalanced.
It seems plausible that transporters, when presented with a mixture of nutrients composed of ions that they transport, would preferentially transport more of the more abundant nutrient, inhibiting the uptake of the less abundant minerals as observed in Arabidopsis for Mn vs.
Fe, and in bean for Zn vs. Fe and Mn Yang et al. Similar to antagonistic interactions among nutrient elements, synergism in nutrient uptake also has been demonstrated. Synergism between P and Mn, as well as between K and Mn, and Mg and Ca, is observed in barley, with increasing P application Matula The occurrence of antagonism or synergism among nutrients demonstrates how fertiliser formulations of specific nutrient composition can influence the overall nutrition of plants.
Therefore, these phenomena ought to be considered when nutrients are formulated into fertilisers, so that compatible nutrients can be leveraged, while antagonistic ones are excluded. In view of the potentially vast impact of fertilisers on food and the environment, Conijn et al.
One approach in the 4R Nutrient Stewardship could be to synchronise the allocation of fertiliser types to soil types and weather conditions that could be identified with generic crop and soil modelling approaches. Systematic analyses of agro-ecosystems, with crop models as one tool, have allowed deeper understanding of the production ecological processes and functioning of these systems Van Ittersum and Rabbinge These findings have governed agricultural investments in developed nations, with current average wheat yield in the Netherlands of over 9.
Crop modelling is being used to identify fertiliser requirements to attain desired yield levels, but the poor resolution of soil data Leenaars ; Hengl et al.
Complementing this approach with geo-spatial analysis based on soil testing and agronomic fertiliser trials would allow for analysing the direct relation between soil properties and the real effects of nutrients on yield, under given management practices.
We recommend this integrated approach with initial research. Soil and plant diagnostic tools, such as mobile spectrometers Shepherd and Walsh and quick assessment kits, should become an integral part of fine-tuning fertiliser recommendations to soil type, and as guide to producers, traders and users, for targeting the most relevant fertiliser types to their regions and production systems.
However, while many claims are made about new devices that rapidly measure soil properties, interpretation may appear cumbersome, as soil properties can be measured in different ways and the relevance of the data is likely to be crop-and environment-specific. This scenario calls for harmonisation and standardisation of data and methodologies.
Also, instant methods for the assessment of nutrient contents of fertilisers are essential to prevent adulteration yet with daunting challenges e.
Perumal et al. We opine that the gap between the intended fertiliser functionality and their actual impact arises from the fact that fertilisers are made by chemists, chemical engineers and industrial processing technologists, following laws of physical and chemical processes, with little input from the knowledge of plant physiology and need for agro-ecological specificity of crop nutrition.
A renewed impetus is, therefore, needed, to arrive at novel ways of packaging and delivering nutrients to plants, based on a better integration of the plant physiological and ecological processes related to the different modes of nutrient uptake, transport and metabolism.
This should be harmonised with timing and quantities of nutrient required for the physiological growth processes, comparable to the packaging and administration of nutrients to humans, in sync with our metabolism. Dependent on environmental conditions, crop specie, developmental stage and health status, plants differentially take up, transport, allocate and assign nutrients different organs.
However, knowledge of the various uptake mechanisms and pathways, whether soil or aerially, has not been adequately harnessed to increase our understanding of the acquisition of nutrients by different food crops for the purpose of targeted and plant-specific fertiliser strategies.
Here, we argue that a more unified knowledge of nutrient biochemical pathways in plants could help in targeting nutrient delivery to where most required and could facilitate further development of viable alternative uptake mechanisms such as foliar fertilisers Voogt et al.
In addition, understanding the ability of plants to increase their nutrient storage capacity could help to increase uptake, yield and food quality Sinclair and Rufty Uptake of nutrient elements as charged ions implies that active transport by proteins is required to move them across the root cell membrane.
Considering that sugars are produced in the leaves prior to root delivery, the form of N applied to crops could cause differential responses in the plant under different environmental conditions Moritsugu et al.
In high-temperature agro-ecological conditions, leaf sugar would be metabolised at a faster rate due to temperature-induced increase in respiration, resulting in less sugar being availed the root for conversion into derived products.
Thus, dependent on environmental conditions, specific plant physiologies should be leveraged to target fertiliser types to crops. As indicated, the role of micronutrients in influencing plant growth and yield, even in the presence of adequate NPK, is becoming increasingly obvious, and nowhere is this more apparent than in the nutrient-poor soils of many African countries Vanlauwe et al.
The uptake of some ionic micronutrients from the soil is preceded by their biological conversion to forms amenable for root uptake. Although both the reductase and phytosiderophore systems are induced in response to Fe deficiency, they are non-specific enough to competitively permit the uptake of other mineral nutrients such as Mn, Zn and Cu Schaaf et al.
Yet, current fertiliser formulations with micronutrients involve their amendment into the main NPK fertilisers, with little, if any, concern about the fate of competing micronutrients in the formulations.
Given the role of micronutrients in crop yield and quality, the influence of specific plant-nutrient physiology on the use efficiency of micronutrient fertiliser formulations deserves not only continuous but also unified research.
Furthermore, the role of specific plant root exudates organic acids, phytosiderophores and reductants in influencing nutrient availability to plants should be rigorously explored as a step not only towards crop-specific fertiliser production but also for integrated soil fertility management practices, such as selecting crop species for beneficial intercropping Badri and Vivanco ; Zuo and Zhang ; Berendsen et al.
Obviously, a clearer understanding of the physiology surrounding plant nutrition should permit the identification of a range of nutrient delivery strategies that ensure both instantaneous plant uptake and administration of the relevant nutrient. As illustrated below Fig. Figure 1 illustrates how the currently fragmented fertilisation regimes could be integrated into a comprehensive system that considers different and complementary fertilisation pathways.
In such a system, field soil or seed-specific nutrient content determinations should direct subsequent application of fertilisers. Consequently, fertilisers for soil application or seed coating should be selected based on their content of nutrients that promote early germination and root growth Smit et al.
In essence, nutrients should be applied to plant areas where they are most physiologically relevant. Soil properties dictate to a very large degree the responses of crops to nutrient elements. The pH of a soil, for example, can determine the extent to which a nutrient is available to plants Marschner Change in pH induced by a fertiliser treatment could also complicate the situation: The alkaline nature of some urea-micronutrient mixed fertilisers could impede nutrient solubility and, therefore, availability, as observed for Zn amended to urea Milani et al.
However, N-fertilisers that acidify the rhizosphere would be suitable for alkaline soils where Fe, Zn and Mn availability are limited. Yet, in many production systems, different fertilisers are applied to soil without proper consideration of soil pH, or the effects of the applied fertiliser on soil pH and thus the availability of other nutrients.
Fortunately, plants can adapt to soil properties in order to enhance their ability to dissolve and take up nutrients from the soil.
These adaptations may feature anatomical, morphological or physiological characteristics in specific environments such as nutrient-poor soils Aerts Morphologically, roots may develop high competitive ability for nutrient uptake through extensive rooting systems.
: Promoting effective nutrient assimilation pathways| Introduction | These coordinated regulations Effectie NLP7 enable plants to rapidly adapt to N availability Promotin maintain Patways N homeostasis. Thanks pathwys Susan Yiapan for help Grape Vine Maintenance manuscript editing. Rate nutriwnt not exceed net crop N requirement and considers previous legume crop, previous manure history, and fertilizer N to be applied regardless of manure e. Finally, we consider the consequences of nutrient deprivation on nutrient-sensitive signalling pathways and its impact for immune function. B55 enhances S content and growth in tobacco seedlings under S-deficient conditions Meldau et al. National Center for Complementary and Integrative Health. |
| Nutrient Management to Improve Nitrogen Efficiency and Reduce Environmental Loss | sativa it increased photorespiration and drought tolerance. More detailed guidance on these requirements can be found in the Pennsylvania Nutrient Management Act Program Technical Manual. The transgenic tobacco plants were generated as previously described 53 and identified by RT-PCR with the primers NLP7 RT-PCR LP and RP. Wang C, Zeng J, Li Y, Hu W, Chen L, Miao Y, et al. Hammond JP, Broadley MR, White PJ, King GJ, Bowen HC, Hayden R, Meacham MC, Mead A, Overs T, Spracklen WP, Greenwood DJ Shoot yield drives phosphorus use efficiency in Brassica oleracea and correlates with root architecture traits. |
| Microbial enhancement of plant nutrient acquisition | Stress Biology | Phosphorylation occurs at more than one residue and increases affinity for the substrate glutamate. In addition to phosphorylation, several chloroplastic enzymes of nitrogen assimilation such as NIR, GS2 and Fd-GOGAT are also redox-regulated through the thioredoxin system for reviews see Lemaire et al. With the aim of improving NUE, many critical candidate genes have been manipulated, over-expressing them or using knockout mutations, in order to test their effects on biomass and plant nitrogen status. Several good reviews have been written on this subject that provide more detail than mentioned in this section Andrews et al. Until now, probably because of strong post-transcriptional controls see above , manipulating nitrate uptake through the over-expression of HATS-like NRT2·1 led to increased nitrate influx under some conditions but did not change the phenotypic NUE or nitrate utilization Fraisier et al. NR has long been considered to be the rate-limiting step in nitrate assimilation. Nicotiana tabaccum plants constitutively expressing NR from N. plumbaginifolia showed delay in NR-activity loss under drought, which allowed them to present a more rapid recovery after short-term water deficit Ferrario-Mery et al. Then, under field conditions of fluctuating water availability, constitutive NR expression may confer some physiological advantage. Over-expressing NR or NiR in Arabidopsis , potato or tobacco reduced nitrate levels in plant tissues but did not increase biomass yield, tuber numbers or seed yields. Over-expression of Nia or Nii genes in plants increased mRNA levels and often affected N uptake without modifying yield or plant growth regardless of the nitrogen source available. This is believed to be due in part to the complex post-transcriptional regulation of NR reviewed by Pathak et al. Over-expression of cytosolic glutamine synthetase GS2 genes was performed in N. tabaccum and Oryza sativa using the Rubisco small subunit promoter and the CaMV 35S promoter, respectively Hoshida et al. tabaccum , over-expression enhanced growth rate and in O. sativa it increased photorespiration and drought tolerance. Attempts to over-express GS1 genes are more numerous and have used different promoter combinations, including CaMV 35S, RolD and small Rubisco subunit rbcS. Effects on plant biomass and grain yield were also more successful. For example, over-expression of the Phaseolus vulgaris GS1 gene under the control of the rbcS promoter in wheat resulted in significantly higher root and grain yield with higher N content in grain in some lines Habash et al. Over-expression of the Pisum sativum GS1 gene under the control of the CaMV 35S promoter in N. tabaccum resulted in biomass and leaf protein increases Oliveira et al. In summary, several studies have demonstrated a direct correlation between an enhanced GS activity in transgenic plants and biomass or yield Good et al. Although over-expression of GOGAT genes has been rare, Yamaya et al. In conclusion, studies show that over-expression of GS or GOGAT genes can improve biomass and grain yields depending on which gene allele and which promoters are used. This indicates that further characterization is required to demonstrate the beneficial effects of such strategies for crops and in field conditions. Attempts to over-express AS were carried out in tobacco and Arabidopsis for a review see Good et al. Interestingly, over-expression of ASN1 in Arabidopsis enhanced soluble seed protein content and total protein and increased fitness of plants grown under nitrogen-limiting conditions Lam et al. Alanine is a major amino acid for nitrogen storage under anaerobic stress such as flooding. Over-expression of barley alanine amino transferase under the control of root promoters in canola and rice had interesting effects, considerably increasing plant biomass, seed yield, NUE and shoot nitrogen concentration when plants were grown at low nitrate supply Good et al. These results are of particular interest, showing that it is possible to improve NUE by manipulating downstream steps in N-remobilization. In addition to manipulating enzymes involved in nitrogen assimilation of amino acid metabolism, the generation of plants modified for the expression of transcription factors has also been attempted. For example, ectopic expression of the maize Dof1 transcription factor, which regulates the expression of genes involved in organic acid metabolism, led in Arabidopsis to the accumulation of amino acids and to an increase of growth under N-limiting conditions. These effects suggest that NUE could also be improved by manipulating carbon metabolism pathways. PII-like, NLP7 and TOR target of rapamycin proteins, which are potentially linked to C and N sensing in plants, are other candidates for further engineering as shown by the increased plant growth, yield and stress resistance acquired by TOR-overexpressing plants Ferrario-Mery et al. Hibberd et al. The Rubisco protein is known to be used as a storage protein in C 3 herbaceous plants and trees Millard et al. In elevated atmospheric CO 2 , Rubisco carboxylase activity is increased and Rubisco protein content is decreased. The selective loss of Rubisco enzyme under elevated CO 2 thus benefits NUE without necessarily significantly changing the leaf C assimilation rate. The lower Rubisco levels in C 4 plants explains why NUE is higher in C 4 crops than in C 3. More than accessions of Arabidopsis , originating from various locations worldwide, are available in stock centres. Probably due to a selective adaptation to original edaphic and climatic environments, they show natural variation of their development and they constitute large genetic and phenotypic resources McKhann et al. Several recent papers have presented the first evidence that natural variation exists for nitrogen metabolism, including nitrogen uptake and nitrogen remobilization. The first clue was provided by the analysis of root plasticity. Studies in Arabidopsis have shown the stimulation of root growth by a localized source of nitrate Robinson, ; Forde and Lorenzo, Walch-Liu and Forde assayed the extent of root stimulation using a small collection of six accessions. This observed variation of root adaptation to nitrogen availability should have consequences for nitrogen uptake in plants. Our recent investigation of natural variation in nitrate uptake and nitrogen remobilization in Arabidopsis gives the second clue Fig. Masclaux-Daubresse and F. Chardon, unpubl. A core-collection of 18 accessions of Arabidopsis was grown under limiting and ample nitrogen nutritive conditions. The aim of this study was to collect data allowing us to monitor the natural variation of N uptake at the vegetative stage and the N-remobilization to the seeds at the reproductive stage depending of nitrogen availability, and also to measure traits related to NUE such as biomass of rosettes at the vegetative stage, seed yield, harvest index and nitrogen concentrations in the different plant material collected at vegetative and reproductive stages. Using all the data collected at low and high nitrogen supply, groups of accessions can be clustered, assembling plants that have similar responses depending on nitrate availability. Surprisingly, for most of the traits measured or computed the variation was higher at high nitrate supply when N uptake and N remobilization are not forced by nitrate limitation. Figure 5 shows schematically the large variation observed between the classes of accessions. The differences between the lowest and highest performing accessions were three-fold for N uptake and six-fold for N remobilization. We also noted interesting correlations between how plants manage N uptake and N metabolism and their biomass. Nitrogen absorption and nitrogen remobilization profiling of five Arabidopsis accessions. A core collection of 18 accessions of Arabidopsis grown with 10 m m nitrate was used to measure traits related to biomass, N uptake, N remobilization and NUE C. Five accessions representative of the main classes found are presented. The small sample of accessions highlights the variation of performances. Plants, such as Col0 or Sha, have a relatively good N uptake. The highest N remobilization score was found in Stw-0 while plants with high N percentage and high biomass were Bur-0 and Tsu The last clue is provided by the Arabidopsis eFP-Browser database, which combines microarray analyses Winter et al. Some experiments included in this database used several accessions Lempe et al. It is possible to select specifically the pattern of genes involved in primary N metabolism. Although plants were cultivated in the same conditions 4-day-old seedlings grown in soil in the glasshouse , the signal intensities of some N genes indeed varied among these accessions Fig. Whether such variation is correlated with N-dependence and NUE remains to be determined. Heat map illustrating the natural variation in expression of genes involved in nitrogen metabolism. Signal levels of N genes in ten accessions were obtained from the Arabidopsis eFP-Browser. For each gene, high expression is depicted as dark shading, and low expression is depicted as light shading. Experiments presented above provide ideas about the various traits that can be measured to explore NUE N-gene transcription levels, N uptake efficiency, NRE, nitrogen content, enzyme activities, biomass and encourage computing data according to a systems biology approach, in order to reveal the functioning of the different modules that constitute nitrogen metabolism adaptation in plants. A better characterization of edaphic environments and the metabolism of different Arabidopsis accessions would consequently allow a better understanding of how these modules are regulated according to the nitrogen availability in soil. Natural variation also exists in crops. Approaches currently performed by breeders to improve varieties for many agronomical traits include QTL mapping and marker-assisted selection. However, it is worth noting that the experiments performed on Arabidopsis presented above have been carried out on wild plants, meaning that the plants studied have not been modified for agronomic criteria and that no adaptive selection has decreased differences between them. Using Arabidopsis rather than highly selected plants such as crops for such approaches should then be more informative. Natural variation of N uptake and N remobilization identified in the model plant Arabidopsis is a source of knowledge that can be useful to transfer to crops. QTLs for NUE and other agronomic traits have been mapped in numerous plant species, including maize, rice and Arabidopsis Hirel et al. QTL mapping for nitrogen-related enzyme activities such as nitrate reductase or glutamine synthetase are rarer. Even more rare is the mapping of N-remobilization or N-influx QTLs because of the difficulty in performing 15 N tracing on large populations. The first report of mapping QTL for N remobilization was in barley using the N-balance method, which requires monitoring the difference in flag leaf N-content between anthesis and maturity [ΔN mg per leaf] Mickelson et al. QTLs explaining the variation of this trait were mapped on chromosomes 6 and 7. Mickelson et al. There was no co-localization between the QTLs for ΔN per leaf and grain protein content. However, the most prominent QTL for grain protein content on barley chromosome 6 appeared to be a potential homologue of the grain protein QTL from durum wheat mapped by Joppa et al. Recently, a wheat QTL was cloned through positional cloning and fine mapping Uauy et al. The locus encodes an NAC transcription factor, NAM-B1, which accelerates leaf senescence and increases nutrient filling in developing grains. The ancestral wild wheat allele is functional whereas modern wheat varieties carry a non-functional NAM-B1 allele. The effect of the chromosome Gpc-B1 region including the NAM-B1 gene was studied further by introgressing the Gcp-B1 locus in hexaploid near-isogenic lines. As a result of Gcp-B1 introgression, significantly lowered straw N concentration at maturity and higher nitrogen harvest index NHI were measured, suggesting that the functional Gcp-B1 allele improves N remobilization and diminishes the amount of nitrogen lost in residual dry remains Brevis and Dubcovsky, University of California, Davis, CA, unpubl. Comparing NAM-B1 knockdown RNAi and control lines showed similar results Waters et al. In the same barley population used by Mickelson et al. QTL co-localization strongly suggested that the major endo- or amino-peptidases were not involved in leaf N remobilization or in the control of grain protein content. By contrast, QTL co-localization suggested that vacuolar carboxy-peptidase isoenzymes are involved in leaf N remobilization. More recently, N-uptake and N-remobilization QTLs have been mapped in maize Coque and Gallais, ; Coque et al. The authors monitored an impressive number of traits for NUE, leaf senescence, enzyme activities, yield, biomass, N uptake and N remobilization, which, together with the former data from Hirel et al. The study by Coque et al. QTL clustering showed an antagonism between N remobilization and N uptake at several loci. Positive coincidences between N uptake, root system architecture and leaf greenness were also found in eight clusters, while N-remobilization QTLs mainly coincided with leaf senescence QTLs. Co-localization with N-related genes showed that the two NR loci chromosomes 1 and 4, see Hirel et al. Grain yield-related traits coincided with the three GS1 loci corresponding to Gln , Gln and Gln The GS2 locus chromosome 10 coincided with a leaf senescence QTL Coque et al. QTLs for NUE and N-enzyme activities were also recently explored in wheat Habash et al. Interestingly, Habash et al. This finding was confirmed by Fontaine et al. Unlike in maize, there was no correlation between GS activity and yield components in wheat. Improving global plant productivity and product quality together with taking care of environmental quality and human wellbeing are the main challenges for the immediate future Vitousek et al. Such a goal depends on agricultural development and policy and can be achieved by providing the right nutrient source at the right rate, the right time and the right place. To improve sustainable agricultural production, it is also necessary to grow crops that can remove the nutrient applied to soil efficiently, and therefore require less fertilizer. This review gives an overview of the different metabolic and physiological clues that agronomical research has provided. The enzymes and regulatory processes that can be manipulated to control NUE are presented. The last results obtained from natural variation and QTL studies show the complexity of NUE and open new perspectives. With regard to the complexity of the challenge we have to face and with regard to the numerous approaches available, the integration of data coming from transcriptomic studies, functional genomics, quantitative genetics, ecophysiology and soil science into explanatory models of whole-plant behaviour in the environment has to be encouraged. We are grateful to Dr Heather I. McKhann INRA, Paris, France for carefully reading the manuscript. Google Scholar. Google Preview. Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Navbar Search Filter Annals of Botany This issue Annals of Botany Company Journals Ecology and Conservation Evolutionary Biology Plant Sciences and Forestry Books Journals Oxford Academic Mobile Enter search term Search. Issues More content Special Issues Advance articles High Impact Research Submit Why Publish with AoB? Author Guidelines Submission Site Open Access Policies Self-Archiving Policy Follow Us X Mastodon Instagram Quarterly Newsletter About About Annals of Botany About the Annals of Botany Company Editorial Board Advertising and Corporate Services Journals Career Network Alerts Purchase Journals on Oxford Academic Books on Oxford Academic. Annals of Botany Company Journals. Author Guidelines Submission Site Open Access Policies Self-Archiving Policy Follow Us X Mastodon Instagram Quarterly Newsletter About About Annals of Botany About the Annals of Botany Company Editorial Board Advertising and Corporate Services Journals Career Network Alerts Purchase Close Navbar Search Filter Annals of Botany This issue Annals of Botany Company Journals Ecology and Conservation Evolutionary Biology Plant Sciences and Forestry Books Journals Oxford Academic Enter search term Search. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Abstract. NITROGEN SOURCES AND UPTAKE. Journal Article. Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. Institut Jean-Pierre Bourgin IJPB UMR , INRA Versailles Cedex, France. E-mail masclaux versailles. Oxford Academic. Françoise Daniel-Vedele. Julie Dechorgnat. Fabien Chardon. Laure Gaufichon. Akira Suzuki. Revision received:. PDF Split View Views. Select Format Select format. ris Mendeley, Papers, Zotero. enw EndNote. bibtex BibTex. txt Medlars, RefWorks Download citation. Permissions Icon Permissions. Close Navbar Search Filter Annals of Botany This issue Annals of Botany Company Journals Ecology and Conservation Evolutionary Biology Plant Sciences and Forestry Books Journals Oxford Academic Enter search term Search. Abstract Background. Nitrogen use efficiency , remobilization , quantitative trait loci , natural variation , nitrate transporter , ammonium assimilation , glutamine synthetase , leaf senescence , nutrient recycling. Open in new tab Download slide. Characterization of the Arabidopsis nitrate transporter NRT1·6 reveals a role of nitrate in early embryo development. Google Scholar Crossref. Search ADS. Can genetic manipulation of plant nitrogen assimilation enzymes result in increased crop yield and greater N-use efficiency? An assessment. A central integrator of transcription networks in plant stress and energy signalling. The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling. Dynamics of light and nitrogen distribution during grain filling within wheat canopy. Putative role of gamma-aminobutyric acid GABA as a longdistance signal in up-regulation of nitrate uptake in Brassica napus L. The nodule inception-like protein 7 modulates nitrate sensing and metabolism in Arabidopsis. Cadmium toxicity induced changes in nitrogen management in Lycopersicon esculentum leading to a metabolic safeguard through an amino acid storage strategy. Mutation of a nitrate transporter, AtNRT, results in a reduced petiole nitrate content and altered leaf development. The Arabidopsis ATNRT2·7 nitrate transporter controls nitrate content in seeds. C and N mobilization from stalk to leaves during kernel filling by 13 C and 15 N tracing in Zea mays L. Genetic variation for nitrogen remobilization and postsilking nitrogen uptake in maize recombinant inbred lines: heritabilities and correlations among traits. Genetic variation of N-remobilization and postsilking N-uptake in a set of maize recombinant inbred lines. QTL detection and coincidences. The expanded family of ammonium transporters in the perennial poplar plant. De Angeli. The Arabidopsis TOR kinase links plant growth, yield, stress resistance and mRNA translation. Nitrogen recycling and remobilization are differentially controlled by leaf senescence and development stage in Arabidopsis under low nitrogen nutrition. N-protein mobilisation associated with the leaf senescence process in oilseed rape is concomitant with the disappearance of trypsin inhibitor activity. Rubiscolytics: fate of Rubisco after its enzymatic function in a cell is terminated. Overexpression of nitrate reductase in tobacco delays drought-induced decreases in nitrate reductase activity and mRNA. 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The genetics of nitrogen use in hexaploid wheat: N utilisation, development and yield. Role of asparagine and asparagine synthetase genes in sunflower Helianthus annuus germination and natural senescence. Using C 4 photosynthesis to increase the yield of rice — rationale and feasibility. Towards a better understanding of the genetic and physiological basis for nitrogen use efficiency in maize. The challenge of improving nitrogen use efficiency in crop plants: towards a more central role for genetic variability and quantitative genetics within integrated approaches. Arabidopsis LHT1 is a high-affinity transporter for cellular amino acid uptake in both root epidermis and leaf mesophyll. Enhanced tolerance to salt stress in transgenic rice that overexpresses chloroplast glutamine synthetase. AtCIPK8, a CBL-interacting protein kinase, regulates the low-affinity phase of the primary nitrate response. Cloning and functional characterization of an Arabidopsis nitrate transporter gene that encodes a constitutive component of low-affinity uptake. Kinetic properties and ammonium-dependent regulation of cytosolic isoenzymes of glutamine synthetase in Arabidopsis. Mapping gene s for grain protein in tetraploid wheat Triticum turgidum L. using a population of recombinant inbred chromosome lines. Post-translational regulation of CND41 protease activity in senescent tobacco leaves. In winter wheat Triticum aestivum L. Overexpression of the ASN1 gene enhances nitrogen status in seeds of Arabidopsis. Using genotype × nitrogen interaction variables to evaluate the QTL involved in wheat tolerance to nitrogen constraints. Enzymatic and metabolic diagnostic of nitrogen deficiency in Arabidopsis thaliana Wassileskija accession. Diversity of flowering responses in wild Arabidopsis thaliana strains. Google Scholar OpenURL Placeholder Text. 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GCN2, an old dog with new tricks. Ravindran, R. Vaccine activation of the nutrient sensor GCN2 in dendritic cells enhances antigen presentation. Science , — The amino acid sensor GCN2 controls gut inflammation by inhibiting inflammasome activation. GCN2 kinase in T cells mediates proliferative arrest and anergy induction in response to indoleamine 2,3-dioxygenase. Immunity 22 , — Fallarino, F. The combined effects of tryptophan starvation and tryptophan catabolites down-regulate T cell receptor zeta-chain and induce a regulatory phenotype in naive T cells. Download references. We apologize to those whose work is not cited due to space limitations. School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, Dublin, D02 R, Ireland. School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, Dublin, D02 R, Ireland. You can also search for this author in PubMed Google Scholar. drafted the text and figures with inputs from N. Both authors revised and finalised the manuscript for publication. Correspondence to David K. Journal peer review information : Nature Communications thanks Ping-Chih Ho and the other, anonymous, reviewer s for their contribution to the peer review of this work. Open Access This article is licensed under a Creative Commons Attribution 4. Reprints and permissions. Kedia-Mehta, N. Competition for nutrients and its role in controlling immune responses. Nat Commun 10 , Download citation. Received : 01 March Accepted : 15 April Published : 09 May Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Nature Reviews Molecular Cell Biology By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily. Skip to main content Thank you for visiting nature. nature nature communications review articles article. Download PDF. Subjects Cell death and immune response Immunology Metabolism Signal transduction. Abstract Changes in cellular metabolism are associated with the activation of diverse immune subsets. Introduction Immune responses involve rapid and extensive changes in the activities of immune cells with concomitant alterations in cellular metabolism. Full size image. Nutrient demands and metabolic configurations Cellular metabolism is a key factor in determining the fate and functions of immune cells. Availability of nutrients within immune microenvironments Tumours have long been known to be highly glycolytic and to have a prodigious appetite for glucose, which is used to support unrestrained tumour growth and proliferation. Consequences of altered nutrient availability: signalling and immune outputs Nutrient-restrictive microenvironments will directly impinge upon metabolic pathways in immune cells, but will also impact upon nutrient-sensitive signalling pathways important in immune regulation. The challenge of in vivo metabolic analysis In vitro or ex vivo metabolic analyses have helped bring forth advances in our understanding of the metabolic phenotypes adopted by immune cells. Article CAS PubMed PubMed Central Google Scholar Murray, P. Article CAS PubMed Google Scholar Loftus, R. Article CAS PubMed Google Scholar Buck, M. Article CAS PubMed PubMed Central Google Scholar Ma, R. Article CAS PubMed Google Scholar Sinclair, L. 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Article CAS PubMed Google Scholar Ho, P. With a limited root system, you could use all of the N management practices discussed here but still have very poor N use efficiency and increased N losses. The nutrient management programs in Pennsylvania have historically been highly coordinated to make it easier for farmers to comply with the different state and federal requirements and to minimize duplication of efforts. Consequently, the Pennsylvania law, Act 38, which regulates concentrated animal operations CAOs , the federal Concentrated Animal Feeding Operations CAFOs regulations, and the Natural Resources Conservation Service NRCS Nutrient Management Practice Standard all utilize the same core nutrient management plan. The Pennsylvania Clean Streams Law requires that all other agricultural operations land-applying manure to also have a plan that is based on similar principles. Thus, all of these nutrient management plans have similar requirements for managing nitrogen. The primary law is Pennsylvania Act 38 of , or the Pennsylvania Nutrient and Odor Management Law. Under Act 38, CAOs are required to develop an approved nutrient management plan, and those plans must address any potential nitrate leaching on the farm. See Pennsylvania's Nutrient Management Act Act 38 : Who Is Affected? and Nutrient Management Legislation in Pennsylvania: A Summary of the Regulations. Under the federal Clean Water Act, CAFOs, which are farms with large numbers of animals regardless of the land base, must have a National Pollutant Discharge Elimination Permit NPDES , which also requires an approved nutrient management plan. In Pennsylvania, the nutrient management plan requirements for a CAFO NPDES permit are the same as the Pennsylvania Act 38 requirements. With the revision of the NRCS Conservation Practice Standard Code Nutrient Management, nitrogen must be managed for leaching risk on all fields by meeting criteria and guidance in the Act 38 regulations, the Act 38 Technical Manual, and Penn State Extension guidance in the Penn State Agronomy Guide and related technical fact sheets. The standard is available in Section IV of the NRCS Field Office Tech Guide. The Pennsylvania Clean Streams Law requires that all farms that produce or utilize manure to have a written Manure Management Plan. These plans can be farmer written and do not have to be approved, but they must be kept on the farm and fully implemented with records to document implementation. Guidance for these plans is provided in the Pennsylvania Manure Management Manual. Plans written to meet Act 38, CAFO regulations, or NRCS requirements satisfy this requirement. The details of the nutrient management requirements for N, as found in the Act 38 regulations and utilized by the other programs described above, are provided below, followed by numbers in brackets to indicate a reference in the regulations. All of these requirements can be found in Act More detailed guidance on these requirements can be found in the Pennsylvania Nutrient Management Act Program Technical Manual. Prepared by Kathryn Clark, soil science honors student, and Douglas Beegle, Distinguished Professor of Agronomy. The store will not work correctly when cookies are disabled. Nutrient Management to Improve Nitrogen Efficiency and Reduce Environmental Loss. This article describes the three main pathways of nitrogen loss--nitrate leaching, denitrification, and volatilization--and summarizes requirements and provides nitrogen management guidance. Download Save for later Print Purchase Guides and Publications. Nutrient Management to Improve Nitrogen Efficiency and Reduce Environmental Loss This article describes the three main pathways of nitrogen loss--nitrate leaching, denitrification, and volatilization--and summarizes requirements and provides nitrogen management guidance. Add to Cart. Updated: September 16, Skip to the end of the images gallery. Skip to the beginning of the images gallery. Fertilizer Management Better Good Fair Not Acceptable by Act 38 Regulations Fertilizer Nitrogen N Fertilizer Rate Rate does not exceed crop N recommendation or N removal by legumes and considers previous legume crop, previous manure history, and planned manure application method and PSNT, chlorophyll meter, or other tests used to adjust sidedress N rate Rate does not exceed crop N recommendation or N removal by legumes and considers previous legume crop, previous manure history, and planned manure application method Rate does not exceed crop N recommendation or N removal by legumes Rate exceeds crop N recommendation and does not consider previous legume crop, previous ma- nure history, and planned manure application N Fertilizer Timing Fertilizer applied in split applications in sync with crop uptake e. Douglas Beegle, Ph. You may also be interested in Guides and Publications. Online Courses. Personalize your experience with Penn State Extension and stay informed of the latest in agriculture. Sign Up for Our Newsletter:. Email address is required to login. Please enter your email address below to create account. Sign In. Rate does not exceed crop N recommendation or N removal by legumes and considers previous legume crop, previous manure history, and planned manure application method and PSNT, chlorophyll meter, or other tests used to adjust sidedress N rate. Rate does not exceed crop N recommendation or N removal by legumes and considers previous legume crop, previous manure history, and planned manure application method. Rate exceeds crop N recommendation and does not consider previous legume crop, previous ma- nure history, and planned manure application. Fertilizer applied in split applications in sync with crop uptake e. Fertilizer applied immediately days prior to planting annual crops or applied earlier weeks to a growing cover crop or applied earlier weeks with a nitrification inhibitor. Fertilizer applied well ahead weeks of planting annual crops with no cover crop or expected uptake by a perennial crop. Fertilizer applied a month or more before planting an annual crop or expected uptake by a perennial crop. Fertilizer not incorporated see "N Fertilizer Incorporation Methods" below for alternatives to incorporation. Fertilizer incorporated by conservation tillage methods or not incorporated and a urease inhibitor used with urea or UAN fertilizer or not incorporated surface band application of UAN or not incorporated but applied immediately before a non-runoff- producing rainfall event. Manure applied on level, well-drained soils far from water with growing crop or 25 percent of crop residue and conservation practices implemented. Manure applied on sloping, well-drained soils with growing crop or 25 percent of crop residue and conservation practices implemented. Manure applied on steep slopes or in areas prone to flooding and excessively well-drained or poorly drained soils. |
| Improving nutrition through biofortification–A systematic review | Figure 3: Enhanced N Promoting effective nutrient assimilation pathways and nitrate uptake in NLP7 -overexpressing plants. Article CAS Promoting effective nutrient assimilation pathways Google Scholar Immune support, L. A lower pathdays content was also asssimilation in a pathwaya mutant, affected in a protein belonging to the Arabidopsis AtCLC ChLoride Channel family. Enrichment of provitamin A content in wheat Triticum aestivum L. Appl Environ Microbiol 82 13 — with abundant soil Mn availability, inoculation with the AM fungus Glomus macrocarpum resulted in strong Mn accumulation, Mn toxicity symptoms and reduced biomass in comparison to control plants Nogueira and Cardoso |
| Regulatory Requirements | Plant, Prromoting Environ — Malnutrition Organic mood enhancers the generic term Promoting effective nutrient assimilation pathways the pathwxys where food nutrients are present in Prlmoting overnutrition or limited quantities undernutrition in the body, leading to adverse health effect 5. The transgenic approach has been shown to be sustainable and rapid when introducing desired traits into crops 25 van der Graaff. Anyone you share the following link with will be able to read this content:. |
Promoting effective nutrient assimilation pathways -
Additionally, in some countries in Latin America and the Caribbean, there is a lack of data related to malnutrition Many countries are usually left out from being included in the analysis, either because research teams are unwilling to participate or because there is no actual data to analyze.
Moreover, anemia remains a public health issue among children under 6 years old and women in most countries for which data are available Finally, other studies indicated that there is a high prevalence of Zn deficiency in children less than 6 years of age and girls and women from 12 to 49 years of age.
High rates of both estimated Zn dietary inadequacy and stunting were also reported in most Latin American and Caribbean countries 57 — It is important to add that to successfully combat hidden hunger through biofortification, even after the development of biofortified varieties, it will be essential to address various socio-political and economic challenges to promote their cultivation and finally their consumption by customers.
For future actions, an integrated approach is required, not only politicians and citizens need to be included but there is also a need to involve farmers, food product developers, dietitians, and educators. These stakeholders can impact population eating habits and contribute to increase the consumption of the target PBFs The adverse effect of malnutrition and hidden hunger has been a global concern for several years forcing several countries to develop interventions.
The Copenhagen Consensus, highlighted that governments and other agencies should prioritize the provision of micronutrients to their populace to serve as one of the best underlying factors for development This has influenced several global initiatives including the New Alliance for Food Security and Nutrition formed in to help promote agricultural growth in Sub-Sahara Africa 10 and the Scaling Up Nutrition Movement sought to fight malnutrition around the globe Several countries have added laws regarding nutrition and health to their constitutions 61 , Generally, there are four interventions that have been adopted in curbing malnutrition and hidden hunger.
These include dietary diversification, food supplementation, food fortification and biofortification 1 , Micronutrients such as Fe, Zn, I 2 , and vitamins are limited in most staples but can be found in certain types of foods 5 , Therefore, consuming a narrow range of foods and more staples with insufficient quantities of micronutrient-rich foods may result in hidden hunger.
This makes dietary diversification a vital strategy that can be used in curbing malnutrition and hidden hunger Dietary diversification or modification pertains the consumption of different varieties of foods with sufficient quantities of macro and micronutrients that synergistically contribute to meeting the RDA over a specific period 6 , 11 , Dietary diversification helps alleviate all forms of deficiencies, aids in boosting the immune system, and is culturally acceptable, and sustainable as compared to other interventions used in alleviating malnutrition and hidden hunger 1 , The major disadvantages of dietary diversification as a strategy of alleviating malnutrition and hidden hunger include the obligation of nutrition education, change in dietary patterns, the need for accurate food data and presence of anti-nutrients in foods consumed, which impact nutrient absorption 6.
Another disadvantage of dietary diversification is the need of financial commitment involved in purchasing and producing high-quality varieties of foods 5 , 67 , Therefore, dietary diversification is very difficult to implement in developing countries; hence other interventions such as food supplementation, food fortification and biofortification are preferred in developing countries 5 , 6.
Food supplementation involves the intake of additional nutrients in the form of capsules, syrups or tablets to add to the nutrients that are obtained from the consumption of foods to meet the RDA requirement 6 , Food supplements include vitamins, amino acids and proteins, essential fatty acids, mineral, fiber, and calorie supplements 69 , In most developing countries, vitamin supplements are most commonly used in combating hidden hunger whilst mineral supplements such as Zn, Fe, and amino acid supplements are less common 5 , 6 , Food supplements are usually targeted to small populations with acute nutrient deficiencies in developing countries.
Food supplementation is also a short-term, direct and controllable strategy, and can be tailored to meet the specific needs of a targeted population. It yields positive results rapidly and is cost-effective as compared to other interventions such as dietary diversification 6 , A population-based study in Ceará, Brazil was conducted to assess the association between vit.
A supplementation and child development using 1, children between the age of 0 and 35 months in 8, households One of the key messages of the study was that vitamin A supplementation had positive effects on child development; indicating food supplementation can be used to improve the nutritional status of a population with micronutrient deficiencies.
Zinc supplementation at infancy increases specific growth outcomes, especially after age 2 Nevertheless, identifying those at risk of Zn deficiency is challenging due to the lack of a reliable diagnostic tool. Another challenge can be reaching rural population as it needs continuous distribution of the supplements Other disadvantages of food supplementation include its reliance on the compliance of the targeted population, require well-defined structures to successfully implement in targeted populations and is highly unsustainable, especially in developing countries 1 , 5 , Food supplementation may also cause toxicity, which has severe effects on the health of targeted populations Food fortification involves the addition of selected nutrients to foods, whether they are naturally present in the foods or not with the purpose of increasing the nutritional value of the foods to help consumers reach the RDA for those nutrients 6 , Both food fortification and food enrichment contribute to increasing the nutritional value of foods, but there is a major difference between them Food enrichment only involves replacing the nutrients lost during the processing of the food, whilst food fortification considers restoring lost nutrients and adding to nutrients that are already present in the food in insufficient amounts.
There are several forms of food fortification; voluntary fortification, mass fortification, mandatory fortification, and target fortification 3.
Voluntary fortification occurs when food processing companies optionally add nutrients to processed foods as it not mandated by the government 3.
A typical example of voluntary fortification is the addition of nutrients such as Fe and vitamin A to breakfast cereals and wheat flours as seen in countries such as Gambia, Qatar and United Arab Emirates 3 , Mass fortification involves the addition of selected nutrients to commonly consumed foods of a specific population with the aim of preventing specific nutrient deficiencies 72 , An example of mass fortification is the fortification of rice which is usually consumed by greater percentage of the population of Asian countries like China 72 , 74 , As suggested by its name, mandatory fortification deals with the addition of nutrients to foods as demanded by the laws and regulations of the government 3 , It is the most common among all forms of fortification.
Most governmental regulations demand the addition of iodine to salts, Fe and folic acid to wheat flour, and vit. A to edible oils 3 , Target fortification has been described as a form of fortification designed specifically for a particular group within a targeted population to reduce a particular nutrient deficiency An example of target fortification is the addition of nutrients such as Fe to infant formulas 74 , Food fortification has become relevant in both developing and developed countries due to the changes in dietary patterns with increases in the consumption of processed foods 3 , 6.
Extensive food processing and storage conditions tend to reduce nutrients such as water-soluble vitamins and minerals of foods Food fortification acts as the medium through which these lost nutrients are restored after processing whilst complementing insufficient nutrients.
Common examples of fortified processed foods include iodized salts, Fe and folic acid-fortified wheat, vitamin D and calcium-fortified milk and, vitamin A-fortified rice and edible oil 3 , 6 , In some contexts, implementation of food fortification is limited due lack of well-structured processing and distribution networks 5 , 16 , Food fortification also tends to favor urban areas rather than rural regions, where there are often communities with higher socioeconomic status, combined with higher levels of health education 16 , Food fortification is measurable, sustainable in developed countries, and implemented at low costs 6 , Fortifying foods with nutrients such as Fe, I 2 and vitamins in developing countries has greatly reduced the prevalence of diseases associated with nutrient deficiencies However, in developing countries, the higher prices of fortified foods makes it less appealing to consumers 67 , Thus, in developing countries, biofortification is considered as a complementary intervention in alleviating malnutrition and hidden hunger.
Biofortification seeks to increase the quantities and bioaccessibility of nutrients in food crops during their growth 65 , It focuses on producing crops with high levels of micronutrients in addition to agronomic traits such as high yield and disease resistance 67 , Biofortification differs from food fortification in that the former involves the addition of nutrients to food crops prior to harvesting whilst the latter adds nutrients to foods during post-harvest processing 3 , Food fortification repeatedly adds nutrients to foods whilst biofortification of varieties of food crops occurs once 74 , Biofortification has been projected to be the most sustainable solution to malnutrition and hidden hunger At present, Harvest Plus, the Biocassava project, and the National Agricultural Research Organization NARO are the major projects initiated for nutritional security via the development of biofortified varieties The initiation of The Harvest Plus Program in , aimed to improve the quality nutritional value of food crops through biofortification The Harvest Plus Program targeted Asia and African countries to ensure the availability and accessibility of high-quality biofortified varieties of staples and the bioavailability of nutrients after consumption 11 , Interventions such as food supplementation and industrial food fortification usually benefit the people of developed and industrialized countries with little to no impact in most developing countries.
On the other hand, biofortification targets the developing and rural world and extends greatly to the developed world as well 5 , 6.
To fully implement biofortification, there is a need to assess the bioavailability of the nutrients, set targeted nutrient levels, assess the nutritional requirement of the targeted population, and enhance the absorption and retention levels of nutrients when subjected to processing and storage conditions 15 , In , a total of 33 million people across Africa, Asia, Latin America, and the Caribbean consumed biofortified crops Common examples of biofortification include OFSP, golden rice, yellow and orange maize biofortified with vitamin A, Zn and Fe biofortified-rice and wheat, and beans 15 , Biofortification programs implemented in most countries have yielded positive results.
In Nigeria, a 6-month study involving two groups of pre-school children aged 3—5 years was conducted. One group was fed with foods prepared using biofortified yellow cassava while the other group was fed with white cassava.
The finding showed that the status of vitamin A determined using serum retinol and hemoglobin concentrations of the group that consumed the biofortified cassava significantly improved relative to the group fed with white cassava While in Rwanda, hemoglobin, serum ferritin, and body Fe levels increased among reproductive women after consuming beans biofortified with Fe 85 Table 1.
Biofortification has certain advantages over other interventions to alleviate malnutrition and hidden hunger. It addresses the nutritional needs of both urban and rural populations and could be implemented at low costs after the initial developmental stages It is the most sustainable method among other interventions 6.
Biofortification of nutrients into food crops has less impacts on their organoleptic properties 16 , The main disadvantage associated with biofortification is its inability to rapidly improve the nutritional status of populations who are highly deficient in nutrients 6.
Global production, consumption, and sales of PBFs have significantly increased Additionally, vegetables can contribute to combating undernutrition, poverty, and hunger, since they can be locally cultivated and consumed Many consumers opt for exclusive PBFs due to the established relationships with health improvement, reduction in environmental impacts, and promoting food security 95 , PBFs have also been shown to provide nutritional benefits, specifically increased fiber, vitamin K and C, folate, magnesium, beta-carotene, and potassium consumption Additionally, Ca, I 2 , and Se present in vegetable-rich diet, are beneficial for optimal bone strength, blood pressure, hormone production, heart, and mental health However, it is important that consumers of exclusive plant-based diets select and combine PBFs to help prevent the risk of micronutrient deficiencies 95 ; particularly vitamin B12 needed for neurological and cognitive health , which is mainly animal-derived nutrient, unless supplemented or provided in Bfortified products PBFs also contain high levels of anti-nutritional factors such as phytates and tannins known to reduce the bioavailability of minerals by preventing their absorption in the intestine Additionally, processes like polishing, milling, and pearling of cereals can reduce their nutritional value Biofortification of PBFs presents a way to reach populations where supplementation and conventional fortification activities may be challenging and may serve as an essential step in preventing nutrient deficiencies, especially among consumers of exclusive PBFs.
Biofortification of PBFs involves increasing the levels of nutrients and their bioavailability. This is dependent on enhancing the bioaccessibility of the nutrients in the soil, uptake and transportation of the nutrients through the plant tissues, and their accumulation in non-toxic quantities in edible parts of the plants 22 , Biofortification of PBFs addresses two main challenges; the inability of the plants to synthesize certain nutrients and the uneven distribution of nutrients in different parts of the plant 22 , For example, the grains of rice are the consumed portion of the rice plant, however, pro-vitamin A synthesis and accumulation occurs in the leaves hence limited in quantities and bioaccessibility in the edible portion.
Therefore, biofortifying the rice plant with pro-vitamin A may enhance its accumulation and bioaccessibility in the grains The Harvest Plus Program has designed suitable steps involved in biofortification of PBFs.
These steps Figure 3 can be grouped into four categories; breeding, nutrition and food technology, impact and socioeconomics, and consumer response 11 , 15 , Figure 3. Harvest plus impact pathway—Plant-based biofortification steps [Modified from ].
For example, Se play important roles and is required in extremely minute quantities in the human body with recommended level of Se intake for adults being 0. Excessive intake of Se causes toxicity which is characterized by adverse health effects such as muscle soreness, intestinal complications, cardiovascular diseases and can extend to extreme cases of mortalities The consumption of biofortified foods should help consumers meet their nutritional needs without any risk of toxicity.
Both bioavailability fraction of nutrient that is stored or available for physiological functions and bioaccessibility fraction of the total nutrient that is potentially available for absorption 80 are important in PB biofortified foods. In a study reported by significant improvement in contents, bioaccessibility and bioavailability of Fe- and Zn-biofortified cowpea cultivars were shown.
The values obtained for Fe bioaccessibility [ In another study, increasing doses of selenate during wheat biofortification enhanced both Se content 0.
However, increasing the selenate doses did not necessarily improve the bioavailability of Se in both apical applications. For the basal application, it increased from Although biofortification might improve micronutrients bioaccessibility in food crops; dietary, physiological, human, and genetic factors can affect the bioavailability of these micronutrients in the human body when consumed — Due to the presence of antinutrients, biofortified crops showed limited improvement in the bioavailability of certain nutrients , It also binds with proteins to form complexes which decrease their solubility, limiting nutrient digestion, release and absorption 25 , To overcome this problem, phytase may be added to degrade phytic acid, reducing its ability to form complexes and, enhance micronutrient absorption Tannins, a polyphenol is mostly found in legumes, berry fruits and cocoa beans thereby causing reduction in Fe bioavailability by forming tannin-Fe complexes 25 , , Lectins are common in legumes, cereals and fruits and can damage the cells of the gut epithelium limiting its efficiency in nutrient absorption , Saponins are commonly found in crops such as legumes, tea leaves and oats, and have the potential to form complexes with sterols which affect the absorption of fat-soluble vitamins such as vitamin A and vitamin E Oxalic acids form strong bonds with Ca, Mg, K, and Na forming soluble or insoluble oxalate salts, which prevent the absorption of these nutrients for metabolic activities , Furthermore, the effects of these anti-nutrients are at sub-lethal levels.
Pre-processing and processing conditions such as soaking, germination, cooking, extrusion, milling, and chemical treatments have been used to reduce the antinutrient contents in foods , , Although these antinutrients negatively affect the absorption of essential nutrients, they have health-promoting properties which could be beneficial to the body Phytate has been shown to have hypoglycemic, anti-inflammatory and anti-carcinogenic properties 25 , Polyphenols aid in removing free-radicals and limiting low density lipoproteins , Lectins promote mitotic cell divisions and destruct cancer-affected cells Saponins have great antimicrobial, cancer-prevention and cholesterol-reducing properties which reduce the risk of cancer and heart diseases , The food environment from which biofortified foods are consumed can influence bioavailability of micronutrients.
When micronutrients are entrapped in macronutrients matrix, their bioavailability may depend on the breakdown of the macronutrient The presence of fats in the food environment promotes the absorption of fats soluble vitamins such as vitamin D, subsequently enhancing Ca absorption Dietary fibers with increased solubility tend to bind with minerals and reduce their bioavailability Age is one of the human factors that influence bioavailability of micronutrients; increasing age decreases the bioavailability of micronutrients Micronutrient absorption may increase at certain periodic stages such as pregnancy, lactation and breastfeeding.
Bioavailability of calcium increases at these stages in women to meet the nutritional requirements of the infant Also, the health condition of consumers may have limiting effects on bioavailability of micronutrients. Conditions such as diabetes, obesity, celiac disease, hypochlorhydria, chronic pancreatitis, and parasite infections limit the absorption of micronutrients , People from different ethnic groups may have variations in genes involved in micronutrient absorption, affecting their bioavailabilities Three biofortification strategies including agronomic intervention, conventional plant breeding and genetic engineering have been described for PBFs 1.
These strategies have been applied to cereals, legumes, oilseeds, vegetables and fruits, with cereals having the largest number of biofortified varieties. Due to limited genetic variability in oilseeds, the transgenic approach is well-suited 14 , Agronomic biofortification involves the application of mineral fertilizers to soil or crops to increase the concentration and bioaccessibility of specific nutrients in the crops Initially, agronomic practices were done to improve the health of crops and increase yield.
However, the importance of nutrition has been highlighted over the years; hence agronomic practices have been expanded to improve the nutritional qualities of crops 5 , 65 , Changes in climate conditions and rapid depletion of soil nutrients is an indication of the need to improve and expand agronomic practices to include improving the nutritional qualities of crops Agronomic biofortification focuses on improving solubilization and mobilization of minerals 55 , The effectiveness of agronomic interventions depends on the soil composition, the solubility and mobility of minerals, the ability of crops to absorb minerals, and the accumulation of bioavailable minerals in non-toxic levels in the edible parts of the crops 25 , 55 , Agronomic biofortification mainly covers minerals and not vitamins because vitamins are synthesized in the crops.
Hence, agronomic biofortification cannot be used as a single strategy in eliminating micronutrient deficiencies and should complement other strategies for effective biofortification 1 , 5 , The use of fertilizers for agronomic biofortification must be performed carefully as an improper application of fertilizer can have unanticipated, and sometimes severe, consequences on the environment and crops.
In contrast, a balanced fertilization strategy is both economically more beneficial and environmentally more sustainable. Additionally, soil microorganisms play a crucial role in the soil ecosystem and are highly sensitive to fertilization.
A deficient fertilization regime results in nutrient deficiency and subsequent modifications of the microbial community of the soil. Unbalanced fertilizations can have detrimental effects on soil biological health over the long-term 55 , Mineral fertilizers are mostly applied to the soil or directly sprayed on the leaf of crops.
The former is more common and applicable when nutrients are required in higher amounts. Foliar application is more economical and applicable when nutrient deficiency symptoms in crops are visible 25 , , when mineral elements are not translocated and accumulated in adequate amounts in the edible parts of the crop 1 , Foliar application tends to be more effective than soil applications because unlike soil application, it increases micronutrient contents rather than just promoting yield 25 , , Foliar application is dependent on several factors including the type of fertilizer, characteristics of crops, time of application, and environmental conditions , Agronomic biofortification of crops with minerals such as Fe and Zn require certain adjustments.
Due to their low mobility, adding metal chelators to the fertilizer is essential 5. Foliar application of FeSO 4 has proven effective for Fe biofortification For I 2 , potassium iodate has been effective as seen in countries like China 5 , , Inorganic fertilizers such as ZnSO 4 , ZnO, and Zn-oxy-sulfate are suitable for Zn agronomic biofortification.
Just like Fe, foliar application of Zn chelators such as ZnEDTA is highly effective — Se is agronomically fortified as selenate which is converted into organic selenomethionine in the crop. Both foliar and soil applications are suitable for Se biofortification, but dependent on soil type and timing of the application However, foliar applications are costly and could easily be rinsed off by raining water , The characteristics of the leaf play an important role in absorbing nutrients during foliar applications.
Nutrients from foliar application penetrate the cuticle to leaf cells and are transported to other parts through the plasmodesmata. The age, structure and permeability of the leaf affect nutrients absorption Foliar application is mostly effective during the flowering and early milk phases than booting and elongation phases of the developmental stages of crops.
The flowering and early milk stages are among the earliest phases where absorption of nutrients for fruit formation begins, hence, foliar application of nutrients at this stage would contribute greatly to increasing the micronutrient contents of the fruits , This was experienced during Zn agronomic biofortification of wheat using foliar application, which was attributed to enhanced phloem mobility and active photo-assimilate allocation to reproductive silk organs that enhanced remobilization of nutrients , , Also, environmental conditions such as time of the day, humidity, temperature, and wind speed affect the efficiency of foliar applications Warm and moist conditions in the early morning and late evening promote permeability of nutrients whilst low relative humidity and high temperature evaporate water from sprayed solution, leading to concentration of minerals on surfaces which reduces mineral permeability Other strategies that are used for agronomic biofortification include coating and priming of seed with mineral fertilizers.
These strategies aid in promoting crop yield and development but have minimal effects on the nutritional qualities of crops 55 , Agronomic biofortification has been used effectively in several countries to combat micronutrient deficiencies and promote agricultural productivity.
The effect of agronomic biofortification of selected underutilized vegetables in Ghana has been assessed Increasing application rate of K fertilizer increased fruits and vegetables weight. Also, the application rate of K fertilizer and the type of K fertilizer synergistically affect K concentration in the fruit.
In another study that assessed the influence of irrigation and fertilizer application on β-carotene yield and productivity of OFSP in South Africa , the total storage root yield increased by 2—3 folds and β-carotene content increased from Agronomic biofortification is simple and yields results rapidly in the short term 5 , However, mineral fertilizers used in agronomic biofortification is costly which increases the prices of biofortified crops, making them inaccessible to poorer populations Also, agronomic biofortification is highly dependent on farmers.
Application of mineral fertilizers is a regular activity hence may be omitted by farmers if they do not gain profits from the process 25 , 80 , Application of mineral fertilizers repeatedly may also cause accumulation, leading to toxicity 1 , In addition, increasing demand for mined minerals such as Se may cause exhaustion and negative impact on the environment 80 , Plant breeding involves producing genetically different or new varieties of crops with improvements in essential micronutrients 55 , , Biofortification through plant breeding aims at improving the concentration and bioaccessibility of minerals in crops by utilizing the genetic differences between crops of similar species 19 , Plant breeding initially focused on promoting yield and improving agronomic traits of crops however, recent plant breeding techniques have been geared toward promoting both the nutritional quality and agronomic traits 54 , Plant breeding techniques should focus on introducing genotypes that would enhance the uptake, transport and redistribution of minerals to improve the efficiency of biofortification In order to achieve this goal, there is a need to enhance mineral mobility in the phloem vessels responsible for redistributing and remobilizing these minerals The translocation and redistribution of Zn from the shoot to fruits or edible portions of crops has been a challenge due to the low mobility of Zn in phloem vessels, leading to lower Zn concentrations in the edible portions as compared to the leaves or the root system 60 , Plants have been bred using three main techniques—conventional, molecular and mutation breeding 25 , Conventional breeding is the most common and accepted form of plant breeding for biofortification 14 , Conventional breeding enhances improvement in the nutritional qualities of crops without compromising other agronomic traits 54 , 55 , Biofortification through conventional breeding involves crossing crops with genotypic characteristics of high nutrient density and other agronomic traits to produce new varieties with desirable nutrient and agronomic traits It requires identifying the biodiverse varieties of crops, assessing traits and amounts of target nutrients in these varieties, and determining the effects of growing conditions on the stability of these traits Currently, about varieties of biofortified cops have been released in over 30 countries via conventional breeding A typical crop biofortified through conventional breeding is OFSP which has been biofortified with pro-vitamin A and with increased yield traits 19 , , Quality Protein Maize QPM is also a product of conventional breeding 25 , Mutation breeding differs from conventional breeding such that, differences in genetic traits among crops are created by introducing mutations through chemical treatments or physical methods such as irradiation 25 , Mutation breeding has been recently adapted to biofortify resistant chickpea mutants like Pusa Ajay , Pusa Atul , Pusa Girnar , and Pusa, developed at I.
Crop improvements via mutation in Pusa include: thin testa, attractive bold seeds, better cooking quality and high yield performance Unlike conventional breeding, differences in genetic traits among crops are created by introducing mutations through chemical treatments or physical methods such as irradiation 25 , Biofortification through molecular breeding involves identification of the position of a gene responsible for improving the nutritional quality and closely linked markers to that specific gene.
With the aid of the marker, the desirable traits can then be bred into the crop using conventional breeding 1 , Molecular breeding can be used to determine if a desirable trait is present or absent in a specific crop during developmental stages.
Hence, it is more rapid as compared to other forms of plant breeding 25 , These varieties have been released in countries such as Zambia, Nigeria and India. Also, it has been reported that several rice varieties have been bred to produce a variety with high Fe and Zn contents and improved agronomic traits Plant breeding is sustainable and less costly as compared to other biofortification strategies 1 , 14 , and financial investments occur only at the research and development stages.
Also, unlike agronomic biofortification, plant breeding has little to no impacts on the environment Consumers generally accept crops that are biofortified through conventional plant breeding and easy to obtain regulatory approval as compared to genetically modified GM foods However, conventional breeding is labor intensive and takes longer time to develop varieties with both desirable traits such as nutrient densities and agronomic traits 19 , Also, there may be limited genetic variations among crops, making it impossible to biofortify these crops via plant breeding 14 , 79 , , and may not be successful for all nutrients.
For instance, breeding varieties of rice with improved vitamin A content initially proved to be challenging, but recent advances in omics technologies have provided the opportunity to practically biofortify varieties of rice with pro-vitamin A Also, crops such as banana that are propagated by vegetative means are not suitable for conventional breeding Plant breeding relies heavily on genetic variations among crops and when variation is limited, it hinders the opportunity of biofortification through plant breeding Unlike plant breeding, genetic engineering is not limited to crops of related species.
Genetic engineering has demonstrated to be a viable solution to this problem 14 , 65 and has been shown to effectively biofortify crops such as banana and rice, which cannot be subjected to conventional plant breeding 79 , , Genetic engineering provides the platform for introducing nutrient or agronomic traits new to specific crop varieties by applying plant breeding and biotechnology principles , and when employed in biofortification, it identifies and characterizes suitable genes which could be introduced into crops to translate into desirable nutritional qualities It utilizes genes from vast array of species, including bacteria, fungi and other organisms.
Certain microorganisms enhance the uptake of nutrients by plants. Genes from these microorganisms can be genetically engineered into crops to enhance nutrient absorption, transportation, and concentration 25 , Fluorescent pseudomonas is a bacterium that enhances plant Fe uptake.
Plants growth-promoting rhizobacteria and mycorrhizal fungi enhance the absorption of minerals from the soils and promote plants growth. Genes from bacteria and Aspergillus species have been used to adjust the lysine and phytate contents of crops such as rice and wheat, respectively 25 , Genome editing, also known as gene editing, corrects, introduces or deletes almost any DNA sequence in many different types of cells and organisms Gene editing provides an opportunity to develop GMOs without the use of transgenes; in addressing regulatory challenges associated with transgenic crops , These off-targets can be overcome by the dimeric nuclease method, which is highly precise and specific According to , low levels of knowledge about gene editing occur because information generated in scientific studies has not been communicated effectively to consumers Biofortification through transgenic approach has been greatly explored in most developed countries.
The most notable example is golden rice which was developed by biofortifying rice with pro-vitamin A 1. This was done by expressing genes encoding phytoene synthase and carotene desaturase which are responsible for β-carotene pathway In golden rice, the expression of these genes caused an increase in pro-vitamin A levels by 1.
The overexpression of Arabidopsis thaliana vacuolar Fe transporter VIT1 in cassava caused fold increase in Fe contents in the storage roots The overexpression of Zn transporters and expression of the gene responsible for phytase activity in barley enhances the levels and bioavailability of Zn 55 , In order to improve the efficiency of the transgenic approach as a biofortification strategy, omics technology has been introduced 20 , Omics technology explains the interrelationship between genes, proteins, transcripts, metabolites, and nutrients 20 — Specific genes control the uptake, transport, concentration, and bioavailability of nutrients by crops.
Hence, genomics omics technology of genes is important since it presents the opportunity to study these specific genes and design suitable ways of improving and inducing them into crops , Transcriptomics omics technology of transcripts aids in conducting full-spectrum analysis to identify a specific expressed gene 20 , , Proteomics omics technology of proteins helps to understand the role of proteins in nutrient synthesis, uptake and transport pathways 21 , Metabolomics omics technology of metabolites aids in assessing metabolic pathways that control the biosynthesis of natural metabolites , , while ionomics considers how minerals present in crops undergo changes in response to genetic and environmental factors These omics technologies have been used in studies involving biofortification of lysine, Ca, Zn, Fe, and vitamin C in PBFs such as maize, finger millet, wheat and tomatoes, respectively PBFs such as cauliflower, cassava, and banana have been biofortified by both transgenic and breeding approaches while barley, soybean, lettuce, canola, carrot, and mustard have been biofortified with transgenic and agronomic approaches The transgenic approach has been shown to be sustainable and rapid when introducing desired traits into crops 25 , Table 2 summarizes a selection of biofortified crops developed by transgenesis.
Biofortification through the transgenic approach has its limitations. The transgenic approach requires huge investments in financial, time and human resources at the research and developmental stages 1 , 5 , Transgenic crops are not generally accepted due to concerns over GMOs 5 , Also, there are several regulations governing the production of transgenic crops Interactions among genes introduced into crops during genetic engineering may reduce the efficacy of the biofortification process 14 , Agronomic biofortification, plant breeding and genetic engineering, including omics technology, are suitable strategies that could be used for plant-based biofortification to help reduce the occurrence of malnutrition and hidden hunger.
The successful implementation of biofortification programs depends on the acceptance of biofortified crops by farmers and consumers The acceptance of GM crops is different for customers and farmers.
In general, consumers have expressed a lower level of acceptance for GM crops and foods, because they are skeptical about the risks and benefits associated with these products , Many factors influence consumer attitudes, including information, trust, beliefs, perceptions of benefits and risks.
Several concerns have been raised about the human health implications from gene flow and transfer, environmental impacts from possible development of resistant weeds and crops, impacts on conventional methods, artificial-like methods, toxicity, and allergenicity of GM crops , It is because of this that genetically engineered plants and their products are often rejected based on unverified grounds.
The overall inclination toward avoidance have been directed toward GM crops, even though several scientific reports have shown that GM crops are safe to consume , Therefore, it may be necessary to create adequate informational programs which would highlight the importance of biofortified-genetically engineered plants and quell misconceptions about GM crops In many parts of the world where biotech seeds are available, farmers are highly embracing and accepting biotech seeds because of the benefits they receive from GM crops Globally, GM crops are governed by different regulations These regulations and legislations have huge effects on the commercialization and adoption of GM crops Strict labeling rules of GM crops have been set by over 40 countries The European Union introduced a very strict authorization system for GM crops and foods over a decade ago, as a precaution.
All food derived from GM plants were required to be labeled based upon the process, even if no traces of the genetic modification could be detected in the purified end-product.
Accordingly, recent trends in many European countries have created an environment that makes the cultivation of GM crops and foods extremely difficult. The US legislation is more lenient in that novel GM foods do not have to be labeled if they do not differ in composition from established non-GM foods.
As with Europe, China has been requiring the labeling of foods derived from GM crops for more than a decade , Also, most agri-business companies patent newly developed GM crops, monopolizing the commercialization of the GM crops.
Several debates have been raised about the motive for developing GM crops—for privatization and profit-making or for the purpose of promoting food security Therefore, regulations and legislations governing GM crops should be adjusted, especially in developing countries, to be less rigorous, and cost and time-effective to promote the adoption of GM crops , In many countries, researchers and seed companies are predicting that new breeding techniques such as intragenesis and cisgenesis, which transfer only genetic information from the same species without transferring foreign genes, but could provide smoother routes to market for plants with improved traits, thereby avoiding the roadblocks presented by transgenic GMOs , These newly developed breeding techniques do not fit within the traditional definition of GMOs, and a debate is taking place in many areas regarding how they should be regulated.
In view of this regulatory uncertainty, it is possible for GM products to be distributed differently in the market and for customer acceptance to differ globally What does the future hold for GM crops? Will there be a universal labeling system for GM crops?
Should there be a change in regulations governing Intellectual property rights of GM crops? The adaptation of GM crops in the production of biodegradable polymers has been discussed. Does this indicate that GM crops have strong positive environmental impacts in the future , ?
The possibility of using transgenic crops as means of providing vaccines and medications can be exploited in the future Can GM crops be adapted to have other desirable traits aside agronomic and nutritional traits?
These questions could be the focal points of future research in promoting the development and commercialization of GM crops. Malnutrition and hidden hunger are both present in developed and developing countries and have devastating effects globally. The recent implications of the global pandemic have shown that food systems need to be adapted to advance global changes that can limit deficiencies in our food supply.
Furthermore, climate change projections predict higher inequality and poverty for developing countries and hence, the need to augment the nutritional content in PBFs. Biofortification is the most sustainable and cost-effective method for alleviating malnutrition. Biofortification of PBFs has been used to produce crops with adequate nutrient density and bioavailability and help to combat hidden hunger.
Through plant breeding, transgenics, and mineral fertilizer applications, micronutrient malnutrition can potentially be tackled. For future actions, an integrated approach is required, where politicians, farmers, food product developers, genetic engineers, dietitians, and educators need to be included in the developing efforts.
One of the biggest challenges of biofortification aside from the methods to strengthen the nutritional value of crops is the public acceptance.
Especially for the transgenic techniques more education and marketing should be invested for the success of biofortified products in the market as only few cultivars are finally released for costumers.
Globally, the specificity of biofortification techniques should tackle regional nutritional challenges and should be chosen based on the likelihood of acceptance of cultural difference in consumers. Overall, biofortification represents a promising group of techniques that can improve the global nutritional wellbeing and lead us closer to minimize hunger and malnutrition.
AA conceptualized the manuscript, crafted the outline, led the manuscript writing, and formatted the final version of the manuscript. KO and SA wrote the initial draft. SA prepared the illustrations. AA and ME reviewed and edited the manuscript. All authors approved the submitted version of the manuscript.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers.
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The leaf anatomical and cellular parameters Franco-Navarro et al. The blue arrows represent the up-regulatory enzymatic responses observed. The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
PP-T, RA, ML, JDF-N, and FD-G performed the experiments, participated in the conception of experiments and research plans, analyzed and plotted the data; PP-T participated in the writing of the article; JC-F participated in the conception of research plans, co-funded to finance the project, supervised the experiments, and participated in the writing of the article; and MR supervised and participated in the performance of the experiments, conceived research plans, co-funded the project and wrote the article.
All authors contributed to the article and approved the submitted version. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research URICI.
Help, expertise and technical assistance of B. Beas, F. Moreno-Racero, D. Romero-Jiménez, E. Sánchez-Rodríguez, M. Rubio-Wilhelmi and J. Ruiz are gratefully acknowledged.
The authors thank at the University of Seville, research, technology and innovation centre CITIUS for the service for the use of electron microscope and also like to thank Dr. Purificación Calvo Dept.
Microbiology, US for her unvaluable help in preparating the samples for microscopy. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers.
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Thank you nutriwnt visiting nature. You are using a psthways version with limited support for Promoting effective nutrient assimilation pathways. To obtain the asismilation experience, we Healthy snacking habits you use a Nuyrient up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Nitrogen is essential for plant survival and growth. Excessive application of nitrogenous fertilizer has generated serious environment pollution and increased production cost in agriculture. Nutriennt availability is a determining factor Effectove crop yield and quality. While fertilization is a major approach for nutient plant nutrition, its efficacy can be limited and the production and application of fertilizers Promoting effective nutrient assimilation pathways nhtrient problems to the environment. A large number of soil microbes are capable of enhancing plant nutrient acquisition and thereby offer environmentally benign solutions to meet the requirements of plant nutrition. Herein we provide summations of how beneficial microbes enhance plant acquisition of macronutrients and micronutrients. By dissecting complex signaling interactions between microbes within the root microbiome, a greater understanding of microbe-enhanced plant nutrition under specific biotic and abiotic stresses will be possible.
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