Expression profiling of Nuclear Factor-Y (NF-Y) transcription factors during dehydration and salt stress in finger millet reveals potential candidate genes for multiple stress tolerance.

MAIN CONCLUSION: Expression profiling of NF-Y transcription factors during dehydration and salt stress in finger millet genotypes contrastingly differing in tolerance levels identifies candidate genes for further characterization and functional studies. The Nuclear Factor-Y (NF-Y) transcription factors are known for imparting abiotic stress tolerance in different plant species. However, there is no information on the role of this transcription factor family in naturally drought-tolerant crop finger millet (Eleusine coracana L.). Therefore, interpretation of expression profiles against drought and salinity stress may provide valuable insights into specific and/or overlapping expression patterns of Eleusine coracana Nuclear Factor-Y (EcNF-Y) genes. Given this, we identified 59 NF-Y (18 NF-YA, 23 NF-YB, and 18 NF-YC) encoding genes and designated them EcNF-Y genes. Expression profiling of these genes was performed in two finger millet genotypes, PES400 (dehydration and salt stress tolerant) and VR708 (dehydration and salt stress sensitive), subjected to PEG-induced dehydration and salt (NaCl) stresses at different time intervals (0, 6, and 12 h). The qRT-PCR expression analysis reveals that the six EcNF-Y genes namely EcNF-YA1, EcNF-YA5, EcNF-YA16, EcNF-YB6, EcNF-YB10, and EcNF-YC2 might be associated with tolerance to both dehydration and salinity stress in early stress condition (6 h), suggesting the involvement of these genes in multiple stress responses in tolerant genotype. In contrast, the transcript abundance of finger millet EcNF-YA5 genes was also observed in the sensitive genotype VR708 under late stress conditions (12 h) of both dehydration and salinity stress. Therefore, the EcNF-YA5 gene might be important for adaptation to salinity and dehydration stress in sensitive finger millet genotypes. Therefore, this gene could be considered as a susceptibility determinant, which can be edited to impart tolerance. The phylogenetic analyses revealed that finger millet NF-Y genes share strong evolutionary and functional relationship to NF-Ys governing response to abiotic stresses in rice, sorghum, maize, and wheat. This is the first report of expression profiling of EcNF-Ys genes identified from the finger millet genome and reveals potential candidate for enhancing dehydration and salt tolerance.

Melatonin-mediated regulation of autophagy is independent of ABA under drought stress in sensitive variety of Gossypium hirsutum L.

Autophagy is a highly conserved process that plays a crucial role in adaptation of plants to stress conditions. Melatonin and abscisic acid (ABA) share an antagonistic relationship; however, both are reported to elevate autophagy individually. Here, we report that melatonin alleviates drought stress effects like wilting and stunted growth in 18-day-old plants of drought-sensitive variety of cotton (Gossypium hirsutum L.) and improves the plant growth, chlorophyll content, photosynthetic efficiency, and sugar metabolism and transport. Melatonin priming increased the endogenous melatonin content (5.02-times) but decreased the ABA (2.63-times) by reducing NCED3 expression as compared to unprimed plants under drought. Also, elevated expression of ATG8c and ATG8f correlated with higher lipidated-ATG8 levels and modulation of RAPTOR1 suggesting a higher occurrence of autophagy and regulation of plant growth in primed stressed plants. Additionally, decreased TPS63 and increased TPP22 expression could have lowered the accumulation of trehalose-6-P (T6P) in primed stressed plants thus contributing to autophagy progression. Priming also enhanced the expression of MAPK6 and RAF18, and increased the transcript/protein levels of SnRK2.6 and KIN10, which is pointing towards melatonin's beneficial effect on autophagy under drought. Despite higher ABA content, elevated TPS63 and downregulated TPP22 could have hindered autophagy induction in unprimed stressed plants. Although fluridone treatment reduced the ABA content, the expression of SnRK2.6 and KIN10 remained unaltered in fluridone-treated and untreated primed plants indicating the ABA-independent expression. These results suggest that the melatonin-mediated activation of MAPK contributes to the ABA-independent activation of SnRK2, consequently, SnRK1 and autophagy under drought.

Histone deacetylase 9 interacts with SiHAT3.1 and SiHDA19 to repress dehydration responses through H3K9 deacetylation in foxtail millet.

Climate change inflicts several stresses on plants, of which dehydration stress severely affects growth and productivity. C4 plants possess better adaptability to dehydration stress; however, the role of epigenetic modifications underlying this trait is unclear. In particular, the molecular links between histone modifiers and their regulation remain elusive. In this study, genome-wide H3K9 acetylation (H3K9ac) enrichment using ChIP-sequencing was performed in two foxtail millet cultivars with contrasting dehydration tolerances (IC403579, cv. IC4-tolerant, and IC480117, cv. IC41-sensitive). It revealed that a histone deacetylase, SiHDA9, was significantly up-regulated in the sensitive cultivar. Further characterization indicated that SiHDA9 interacts with SiHAT3.1 and SiHDA19 to form a repressor complex. SiHDA9 might be recruited through the SiHAT3.1 recognition sequence onto the upstream of dehydration-responsive genes to decrease H3K9 acetylation levels. The silencing of SiHDA9 resulted in the up-regulation of crucial genes, namely, SiRAB18, SiRAP2.4, SiP5CS2, SiRD22, SiPIP1;4, and SiLHCB2.3, which imparted dehydration tolerance in the sensitive cultivar (IC41). Overall, the study provides mechanistic insights into SiHDA9-mediated regulation of dehydration stress response in foxtail millet.

Multi-environment GWAS identifies genomic regions underlying grain nutrient traits in foxtail millet (Setaria italica).

KEY MESSAGE: A total of 104 foxtail millet accessions were evaluated for 11 nutrients in three environments and 67 high-confidence marker-trait associations (MTAs) were identified. Six SNPs showed pleiotropic effect and associated with two or more nutrients, whereas 24 candidate genes were identified for 28 MTAs involving seven traits. Millets are known for their better nutritional profiles compared to major cereals. Foxtail millet (Setaria italica) is rich in nutrients essential to circumvent malnutrition and hidden hunger. However, the genetic determinants underlying this trait remain elusive. In this context, we evaluated 104 diverse foxtail millet accessions in three different environments (E1, E2, and E3) for 11 nutrients and genotyped with 30K SNPs. The genome-wide association study showed 67 high-confidence (Bonferroni-corrected) marker-trait associations (MTAs) for the nutrients except for phosphorus. Six pleiotropic SNPs were also identified, which were associated with two or more nutrients. Around 24 candidate genes (CGs) were identified for 28 MTAs involving seven nutrients. A total of 17 associated SNPs were present within the gene region, and five (5) were mapped in the exon of the CGs. Significant SNPs, desirable alleles and CGs identified in the present study will be useful in breeding programmes for trait improvement.

Genetic enhancement of climate-resilient traits in small millets: A review.

Agriculture is facing the challenge of feeding the ever-growing population that is projected to reach ten billion by 2050. While improving crop yield and productivity can address this challenge, the increasing effects of global warming and climate change seriously threaten agricultural productivity. Thus, genomics and genome modification technologies are crucial to improving climate-resilient traits to enable sustained yield and productivity; however, significant research focuses on staple crops such as rice, wheat, and maize. Crops that are naturally climate-resilient and nutritionally superior to staple cereals, such as small millets, remain neglected and underutilized by mainstream research. The ability of small millets to grow in marginal regions having limited irrigation and poor soil fertility makes these crops a better choice for cultivation in arid and semi-arid areas. Hence, mainstreaming small millets for cultivation and using omics technologies to dissect the climate-resilient traits to identify the molecular determinants underlying these traits are imperative for addressing food and nutritional security. In this context, the review discusses the genomics and genome modification approaches for dissecting key traits in small millets and their application for improving these traits in cultivated germplasm. The review also discusses biofortification for nutritional security and machine-learning approaches for trait improvement in small millets. Altogether, the review provides a roadmap for the effective use of next-generation approaches for trait improvement in small millets. This will lead to the development of improved varieties for addressing multiple insecurities prevailing in the present climate change scenario.

Biotechnological interventions for improving the seed longevity in cereal crops: progress and prospects.

Seed longevity is a measure of the viability of seeds during long-term storage and is crucial for germplasm conservation and crop improvement programs. Also, longevity is an important trait for ensuring food and nutritional security. Thus, a better understanding of various factors regulating seed longevity is requisite to improve this trait and to minimize the genetic drift during the regeneration of germplasm. In particular, seed deterioration of cereal crops during storage adversely affects agricultural productivity and food security. The irreversible process of seed deterioration involves a complex interplay between different genes and regulatory pathways leading to: loss of DNA integrity, membrane damage, inactivation of storage enzymes and mitochondrial dysfunction. Identifying the genetic determinants of seed longevity and manipulating them using biotechnological tools hold the key to ensuring prolonged seed storage. Genetics and genomics approaches had identified several genomic regions regulating the longevity trait in major cereals such as: rice, wheat, maize and barley. However, very few studies are available in other Poaceae members, including millets. Deploying omics tools, including genomics, proteomics, metabolomics, and phenomics, and integrating the datasets will pinpoint the precise molecular determinants affecting the survivability of seeds. Given this, the present review enumerates the genetic factors regulating longevity and demonstrates the importance of integrated omics strategies to dissect the molecular machinery underlying seed deterioration. Further, the review provides a roadmap for deploying biotechnological approaches to manipulate the genes and genomic regions to develop improved cultivars with prolonged storage potential.

SiHSFA2e regulated expression of SisHSP21.9 maintains chloroplast proteome integrity under high temperature stress.

High temperature-induced crop failures are prominent nowadays in major staples, including rice, wheat, and maize; however, crops such as foxtail millet (Setaria italica) are resilient to temperature stress. In this study, a novel small heat shock protein of foxtail millet, SisHSP21.9, is identified and characterized for its role in conferring tolerance to high-temperature stress. SisHSP21.9 is a panicoid-specific gene, which is highly upregulated during high-temperature in leaves, and the protein is localized in the chloroplast. Its expression is directly regulated by heat shock factor, SiHSFA2e, during temperature stress. Further, overexpression of SiHSP21.9 in rice enhanced the survival of transgenics during high-temperature stress (> 80% survival frequency), and the transgenic lines showed improved plant architecture and overall grain yield. Compared to WT plants, transgenic lines maintained optimal photosynthesis rates with higher photosystem efficiencies at high temperatures, and this is conferred through protecting the components of photosystems, chlorophyll-binding proteins, and chloroplast-localized functional proteins by SisHSP21.9. Prolonged high-temperature stress showed minimal damage to chloroplast proteins resulting in comparatively lower yield loss (35-37%) in transgenic lines. Altogether, the study suggests that SisHSP21.9 is a potential candidate for designing thermotolerant crops for climate-resilient agriculture; however, further research is needed because tolerance to abiotic stresses is polygenic.

Modulating physiological and transcriptional regulatory mechanisms for enhanced climate resilience in cereal crops.

Climate change adversely affects the yield and productivity of cereal crops, which consequently impacts food security. Therefore, studying stress acclimation, particularly transcriptional patterns and morpho-physiological responses of cereal crops to different stresses, will provide insights into the molecular determinants underlying climate resilience. The availability of advanced tools and approaches has enabled the characterization of plants at morphological, physiological, biochemical, and molecular levels, which will lead to the identification of genomic regions regulating the stress responses at these levels. This will further facilitate using transgenic, breeding, or genome editing approaches to manipulate the identified regions (genes, alleles, or QTLs) to enhance stress resilience. Next-generation sequencing approaches have advanced the identification of causal genes and markers in the genomes through forward or reverse genetics. In this context, the review enumerates the progress of dissecting the molecular mechanisms underlying transcriptional and physiological responses of major cereals to climate-induced stresses. The review systematically discusses different tools and approaches available to study the response of plants to various stresses and identify the molecular determinants regulating stress-resilience. Further, the application of genomics-assisted breeding, transgene-, and targeted editing-based approaches for modulating the genetic determinants for enhanced climate resilience has been elaborated.

Multi-omics intervention in Setaria to dissect climate-resilient traits: Progress and prospects.

Millets constitute a significant proportion of underutilized grasses and are well known for their climate resilience as well as excellent nutritional profiles. Among millets, foxtail millet (Setaria italica) and its wild relative green foxtail (S. viridis) are collectively regarded as models for studying broad-spectrum traits, including abiotic stress tolerance, C4 photosynthesis, biofuel, and nutritional traits. Since the genome sequence release, the crop has seen an exponential increase in omics studies to dissect agronomic, nutritional, biofuel, and climate-resilience traits. These studies have provided first-hand information on the structure, organization, evolution, and expression of several genes; however, knowledge of the precise roles of such genes and their products remains elusive. Several open-access databases have also been instituted to enable advanced scientific research on these important crops. In this context, the current review enumerates the contemporary trend of research on understanding the climate resilience and other essential traits in Setaria, the knowledge gap, and how the information could be translated for the crop improvement of related millets, biofuel crops, and cereals. Also, the review provides a roadmap for studying other underutilized crop species using Setaria as a model.

Melatonin Mediated Differential Regulation of Drought Tolerance in Sensitive and Tolerant Varieties of Upland Cotton (Gossypium hirsutum L.).

Melatonin (N-acetyl-5-methoxytryptamine), a biomolecule with multifunctional phyto-protectant activities, enhances the tolerance to broad-spectrum biotic and abiotic stresses in plants. However, little information is available on the effect of melatonin on different morpho-physiological, biochemical, and molecular parameters during drought stress incidence in varieties contrastingly differing in their tolerance levels. The present study is aimed at investigating the drought stress responses of drought-sensitive (var. L-799) and drought-tolerant (var. Suraj) varieties after exogenous melatonin priming and gaining mechanistic insights into drought tolerance in upland cotton (Gossypium hirsutum). Melatonin-priming enhanced the tolerance of L-799 to drought stress by modulating the antioxidant system, with increased photosynthetic activity, water-use efficiency, and nitrogen metabolism. Higher endogenous melatonin content and upregulated expression of candidate stress-responsive genes in primed L-799 suggested their involvement in drought tolerance. The higher expression of autophagosome marker [lipidated (ATG8-PE)] in melatonin-primed drought-stressed plants of L-799 also indicated the role of autophagy in alleviating drought stress. Interestingly, melatonin-priming did not show pronounced differences in the different parameters studied during the presence or absence of drought stress in Suraj. In conclusion, this study showed that melatonin plays an important role in mitigating drought stress effects by modulating several physiological, biochemical, and molecular processes, with the key regulatory factor being the plant tolerance level that serves as the switch that turns the priming effects on/off.

Genome Editing and Designer Crops for the Future.

Domestication spanning over thousands of years led to the evolution of crops that are being cultivated in recent times. Later, selective breeding methods were practiced by human to produce improved cultivars/germplasm. Classical breeding was further transformed into molecular- and genomics-assisted breeding strategies, however, these approaches are labor-intensive and time-consuming. The advent of omics technologies has facilitated the identification of genes and genetic determinants that regulate particular traits allowing the direct manipulation of target genes and genomic regions to achieve desirable phenotype. Recently, genome editing technologies such as meganucleases (MN), zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR (clustered regularly interspaced short palindromic repeats)/CRISPR-Associated protein 9 (Cas9) have gained popularity for precise editing of genes to develop crop varieties with superior agronomic, physiological, climate-resilient, and nutritional traits. Owing to the efficiency and precision, genome editing approaches have been widely used to design the crops that can survive the challenges posed by changing climate, and also cater the food and nutritional requirements for ever-growing population. Here, we briefly review different genome editing technologies deployed for crop improvement, and the fundamental differences between GE technology and transgene-based approach. We also summarize the recent advances in genome editing and how this radical expansion can complement the previously established technologies along with breeding for creating designer crops.

De novo transcriptome analysis identifies key genes involved in dehydration stress response in kodo millet (Paspalum scrobiculatum L.).

Kodo millet (Paspalum scrobiculatum L.) is a small millet species known for its excellent nutritional and climate-resilient traits. To understand the genes and pathways underlying dehydration stress tolerance of kodo millet, the transcriptome of cultivar 'CO3' subjected to dehydration stress (0 h, 3 h, and 6 h) was sequenced. The study generated 239.1 million clean reads that identified 9201, 9814, and 2346 differentially expressed genes (DEGs) in 0 h vs. 3 h, 0 h vs. 6 h, and 3 h vs. 6 h libraries, respectively. The DEGs were found to be associated with vital molecular pathways, including hormone metabolism and signaling, antioxidant scavenging, photosynthesis, and cellular metabolism, and were validated using qRT-PCR. Also, a higher abundance of uncharacterized genes expressed during stress warrants further studies to characterize this class of genes to understand their role in dehydration stress response. Altogether, the study provides insights into the transcriptomic response of kodo millet during dehydration stress.

Loss of Function of OsFBX267 and OsGA20ox2 in Rice Promotes Early Maturing and Semi-Dwarfism in γ-Irradiated IWP and Genome-Edited Pusa Basmati-1.

Targeted mutagenesis is now becoming the most favored methodology to improve traits in popular rice cultivars selectively. Understanding the genetic basis of already available mutants could be the first step in designing such experiment. Improved White Ponni (IWP), a popularly grown South Indian rice variety, was subjected to γ irradiation to develop WP-22-2, an M6 line superior in semi-dwarfism, early flowering, and high yield, and it has grain qualities similar to those of IWP. The exogenous application of gibberellic acid (GA3) on WP-22-2 resulted in the elongation of shorter internodes to a level similar to IWP. The expression profiling of six genes regulating plant height showed their differential expression pattern at different time points post GA3 treatment. Furthermore, the sequencing of WP-22-2 and IWP genomes revealed several single nucleotide polymorphisms (SNPs) and large-scale deletions in WP-22-2. The conversion of functional codons to stop codons was observed in OsGA20ox2 and OsFBX267, which have been reported to have roles in regulating semi-dwarfism and early flowering, respectively. The loss of function of OsGA20ox2 and OsFBX267 in WP-22-2 resulted in reduced plant height as well as early flowering, and the same has been confirmed by editing OsGA20ox2 in the rice variety Pusa Basmati1 (PB1) using the CRISPR-Cas9 approach. The targeted editing of OsGA20ox2 in PB1 conferred shorter plant height to the edited lines compared with the wild type. Altogether, the study provides evidence on mutating OsGA20ox2 and OsFBX267 genes to develop early maturing and semi-dwarf varieties that can be released to farmers after functional characterization and field trials.

Identification of suitable reference genes for expression profiling studies using qRT-PCR in an important insect pest, Maruca vitrata.

BACKGROUND: Maruca vitrata is one of the potential insect pests that cause devastating losses to legume cultivation worldwide. Gene functional studies facilitate dissecting the molecular mechanisms underlying the infection process and enable devising appropriate molecular strategies to control this insect pest. Expression profiling using quantitative real-time PCR (qRT-PCR) provides insights into the functional characterization of target genes; however, ideal reference genes should be deployed in such studies to nullify the background variation and improve the accuracy of target gene expression. An ideal reference gene should have a stable expression across developmental stages, biological conditions, tissues, or experimental conditions. METHODS AND RESULTS: Given this, the stability of eight candidate reference genes was evaluated in M. vitrata at different developmental stages, diets, and sexes by qRT-PCR method, and the data was analyzed using four independent algorithms, namely GeNorm, NormFinder, BestKeeper, and ΔCt, and one comprehensive algorithm, RefFinder. CONCLUSION: The analysis showed that RP49 and RPL13 were the best suitable reference genes for studying target gene expression at different developmental stages. Further, the study identified RP49 and RPL24, and GAPDH and RPL24 as the ideal reference genes in M. vitrata fed with different diets and sexes, respectively. The reference genes reported in the present study will ensure the accuracy of target gene expression, and thus, will serve as an important resource for gene functional studies in M. vitrata.

Hormonal crosstalk in regulating salinity stress tolerance in graminaceous crops.

Soil salinity is one of the major threats that pose challenges to global cereal productivity and food security. Cereals have evolved sophisticated mechanisms to circumvent stress at morpho-physiological, biochemical, and molecular levels. Salt stress cues are perceived by the roots, which trigger the underlying signaling pathways that involve phytohormones. Each phytohormone triggers a specific signaling pathway integrated in a complex manner to produce antagonistic, synergistic, and additive responses. Phytohormones induce salt-responsive signaling pathways to modulate various physiological and anatomical mechanisms, including cell wall repair, apoplastic pH regulation, ion homeostasis, root hair formation, chlorophyll content, and leaf morphology. Exogenous applications of phytohormones moderate the adverse effects of salinity and improve growth. Understanding the complex hormonal crosstalk in cereals under salt stress will advance the knowledge about cooperation or antagonistic mechanisms among hormones and their role in developing salt-tolerant cereals to enhance the productivity of saline agricultural land. In this context, the present review focuses on the mechanisms of hormonal crosstalk that mediate the salt stress response and adaptation in graminaceous crops.

A rapid, efficient, and low-cost BiFC protocol and its application in studying in vivo interaction of seed-specific transcription factors, RISBZ and RPBF.

Proteins regulate cellular and biological processes in all living organisms. More than 80% of the proteins interact with one another to perform their respective functions; therefore, studying the protein-protein-interaction has gained attention in functional characterization studies. Bimolecular fluorescence complement (BiFC) assay is widely adopted to determine the physical interaction of two proteins in vivo. Here, we developed a simple, yet effective BiFC assay for protein-protein-interaction using transient Agrobacterium-mediated-transformation of onion epidermal cells by taking case study of Rice-P-box-Binding-Factor (RPBF) and rice-seed-specific-bZIP (RISBZ) in vivo interaction. Our result revealed that both the proteins, i.e., RISBZ and RPBF, interacted in the nucleus and cytosol. These two transcription factors are known for their coordinate/synergistic regulation of seed-protein content via concurrent binding to the promoter region of the seed storage protein (SSP) encoding genes. We further validated our results with BiFC assay in Nicotiana by agroinfiltration method, which exhibited similar results as Agrobacterium-mediated-transformation of onion epidermal cells. We also examined the subcellular localization of RISBZ and RPBF to assess the efficacy of the protocol. The subcellular localization and BiFC assay presented here is quite easy-to-follow, reliable, and reproducible, which can be completed within 2-3 days without using costly instruments and technologies that demand a high skill set.

The Sw5a gene confers resistance to ToLCNDV and triggers an HR response after direct AC4 effector recognition.

Several attempts have been made to identify antiviral genes against Tomato leaf curl New Delhi virus (ToLCNDV) and related viruses. This has led to the recognition of Ty genes (Ty1-Ty6), which have been successful in developing virus-resistant crops to some extent. Owing to the regular appearance of resistance-breaking strains of these viruses, it is important to identify genes related to resistance. In the present study, we identified a ToLCNDV resistance (R) gene, SlSw5a, in a ToLCNDV-resistant tomato cultivar, H-88-78-1, which lacks the known Ty genes. The expression of SlSw5a is controlled by the transcription factor SlMyb33, which in turn is regulated by microRNA159 (sly-miR159). Virus-induced gene silencing of either SlSw5a or SlMyb33 severely increases the disease symptoms and viral titer in leaves of resistant cultivar. Moreover, in SlMyb33-silenced plants, the relative messenger RNA level of SlSw5a was reduced, suggesting SlSw5a is downstream of the sly-miR159-SlMyb33 module. We also demonstrate that SlSw5a interacts physically with ToLCNDV-AC4 (viral suppressor of RNA silencing) to trigger a hypersensitive response (HR) and generate reactive oxygen species at infection sites to limit the spread of the virus. The "RTSK" motif in the AC4 C terminus is important for the interaction, and its mutation completely abolishes the interaction with Sw5a and HR elicitation. Overall, our research reports an R gene against ToLCNDV and establishes a connection between the upstream miR159-Myb33 module and its downstream target Sw5a to activate HR in the tomato, resulting in geminivirus resistance.

Genetic determinants of micronutrient traits in graminaceous crops to combat hidden hunger.

KEY MESSAGE: Improving the nutritional content of graminaceous crops is imperative to ensure nutritional security, wherein omics approaches play pivotal roles in dissecting this complex trait and contributing to trait improvement. Micronutrients regulate the metabolic processes to ensure the normal functioning of the biological system in all living organisms. Micronutrient deficiency, thereby, can be detrimental that can result in serious health issues. Grains of graminaceous crops serve as an important source of micronutrients to the human population; however, the rise in hidden hunger and malnutrition indicates an insufficiency in meeting the nutritional requirements. Improving the elemental composition and nutritional value of the graminaceous crops using conventional and biotechnological approaches is imperative to address this issue. Identifying the genetic determinants underlying the micronutrient biosynthesis and accumulation is the first step toward achieving this goal. Genetic and genomic dissection of this complex trait has been accomplished in major cereals, and several genes, alleles, and QTLs underlying grain micronutrient content were identified and characterized. However, no comprehensive study has been reported on minor cereals such as small millets, which are rich in micronutrients and other bioactive compounds. A comparative narrative on the reports available in major and minor Graminaceae species will illustrate the knowledge gained from studying the micronutrient traits in major cereals and provides a roadmap for dissecting this trait in other minor species, including millets. In this context, this review explains the progress made in studying micronutrient traits in major cereals and millets using omics approaches. Moreover, it provides insights into deploying integrated omics approaches and strategies for genetic improvement in micronutrient traits in graminaceous crops.