Browsing by Author "Muthamilarasan, Mehanathan"

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Advances in plant sciences for nutritional security
(Astral International Pvt. Ltd., 2015) Muthamilarasan, Mehanathan; Prasad, Manoj
Malnutrition and hunger among the world population at alarming rates pose serious threat to global food security. Further, the FAO Hunger Report (2012) depicts that, about 12.5 per cent of the global population (one in eight people) is starving, excluding 100 million children under the age of five. Irrespective of the adults, about 2.5 million children die every year due to starvation and malnutrition which ultimately hinder human potential (FAO Hunger Report 2012). Since, plants are the primary producers in the food chain, they serve as versatile biochemical factories capable of producing almost complete complement of essential dietary micronutrients. However, the dietary micronutrients are unevenly disseminated among different plant parts. For instance, iron content in a rice leaf is as high as 100–200 ppm (parts per million), but very low in the polished rice grain (~3 ppm) (Mayer et al., 2008). Similarly, provitamin A carotenoids are present only in rice leaves but not in its edible part. Unfortunately, economically backward people rely predominantly on starchy staples such as rice, wheat, maize, or cassava, but these crops do not supplement the biochemical diversity needed for a healthy life which leads to micronutrient malnutrition (MNM). Plant science has a central role in addressing these issues of both hunger and malnutrition. Since, MNM affects more than half of the world population, biofortification offers an economical and sustainable approach of delivering micronutrients via micronutrient-dense crops to the human population. Hence, this book chapter summarizes the strategies of generating biofortified-crop plants along with the significant achievements reported in biofortification of major crop plants such as orange sweet potato, maize, cassava, rice, wheat and other crops like lentils, banana, cowpea, sorghum and potato.
Advances in Setaria genomics for genetic improvement of cereals and bioenergy grasses
(Springer, 2015) Muthamilarasan, Mehanathan; Prasad, Manoj
Recent advances in Setaria genomics appear promising for genetic improvement of cereals and biofuel crops towards providing multiple securities to the steadily increasing global population. The prominent attributes of foxtail millet (Setaria italica, cultivated) and green foxtail (S. viridis, wild) including small genome size, short life-cycle, in-breeding nature, genetic close-relatedness to several cereals, millets and bioenergy grasses, and potential abiotic stress tolerance have accentuated these two Setaria species as novel model system for studying C4 photosynthesis, stress biology and biofuel traits. Considering this, studies have been performed on structural and functional genomics of these plants to develop genetic and genomic resources, and to delineate the physiology and molecular biology of stress tolerance, for the improvement of millets, cereals and bioenergy grasses. The release of foxtail millet genome sequence has provided a new dimension to Setaria genomics, resulting in large-scale development of genetic and genomic tools, construction of informative databases, and genome-wide association and functional genomic studies. In this context, this review discusses the advancements made in Setaria genomics, which have generated a considerable knowledge that could be used for the improvement of millets, cereals and biofuel crops. Further, this review also shows the nutritional potential of foxtail millet in providing health benefits to global population and provides a preliminary information on introgressing the nutritional properties in graminaceous species through molecular breeding and transgene-based approaches.
Advances in wheat genomics and its potential in ensuring food security in the scenario of climate change
(Indian National Science Academy, 2014) Muthamilarasan, Mehanathan; Parida, Swarup K.; Prasad, Manoj
Prevalence of hunger and under-nutrition among the world population at alarming rates challenges the food security. Further, the instability in global wheat production in past two years and the projection of continuing decrease in wheat inventories predominantly due to climate change add-up to food insecurity. The global climate change imposing biotic and abiotic stress made the crop improvement more challenging. However, the timely release of wheat genome sequence holds the promise of evading these tribulations, provided the researchers and breeders pertinently utilize the genome information. In view of this, this short-review highlights the intact insights for the wheat research community on how to implement the genome sequence data in breeding and engineering transgenic wheat with enhanced biotic and abiotic stress tolerance.
Application of genomics-assisted breeding for generation of climate resilient crops: progress and prospects
(Frontiers Media S.A., 2015) Kole, Chittaranjan; Muthamilarasan, Mehanathan; Henry, Robert; Edwards, David; Sharma, Rishu; Abberton, Michael; Batley, Jacqueline; Bentley, Alison; Blakeney, Michael; Bryant, John; Cai, Hongwei; Cakir, Mehmet; Cseke, Leland J.; Cockram, James; Oliveira, Antonio Costa de; Pace, Ciro De; Dempewolf, Hannes; Ellison, Shelby; Gepts, Paul; Greenland, Andy; Hall, Anthony; Hori, Kiyosumi; Hughes, Stephen; Humphreys, Mike W.; Iorizzo, Massimo; Ismail, Abdelbagi M.; Marshall, Athole; Mayes, Sean; Nguyen, Henry T.; Ogbonnaya, Francis C.; Ortiz, Rodomiro; Paterson, Andrew H.; Simon, Philipp W.; Tohme, Joe; Tuberosa, Roberto; Valliyodan, Babu; Varshney, Rajeev K.; Wullschleger, Stan D.; Yano, Masahiro; Prasad, Manoj
Climate change affects agricultural productivity worldwide. Increased prices of food commodities are the initial indication of drastic edible yield loss, which is expected to increase further due to global warming. This situation has compelled plant scientists to develop climate change-resilient crops, which can withstand broad-spectrum stresses such as drought, heat, cold, salinity, flood, submergence and pests, thus helping to deliver increased productivity. Genomics appears to be a promising tool for deciphering the stress responsiveness of crop species with adaptation traits or in wild relatives toward identifying underlying genes, alleles or quantitative trait loci. Molecular breeding approaches have proven helpful in enhancing the stress adaptation of crop plants, and recent advances in high-throughput sequencing and phenotyping platforms have transformed molecular breeding to genomics-assisted breeding (GAB). In view of this, the present review elaborates the progress and prospects of GAB for improving climate change resilience in crops, which is likely to play an ever increasing role in the effort to ensure global food security.
Barley genome sequence emerges as a promising candidate in genetic research and breeding
(Indian Academy of Sciences, 2013) Muthamilarasan, Mehanathan; Prasad, Manoj
Barley (Hordeum vulgare L.), domesticated since 8000 BC in western Asia and Northeast Africa (Fertile Cresent), is regarded as the founder crop of Old World agriculture. Cultivated barley is derived from its wild progenitor Hordeum spontaneum C. Koch, still inhabiting the Fertile Crescent from Israel and Jordan to South Turkey, Iraqi Kurdistan, and southwestern Iran. It possesses a distinct phenotype of broader leaves, shorter stem and awns, tough ear rachis, a shorter and thicker spike, and larger grains2. Barley is the fourth largest cultivated cereal worldwide, both in terms of area harvested (1.9 m ha) and production (134 million tonnes; mt). Of its total production, 75% is used as animal feed, 20% processed into alcoholic and non-alcoholic beverages and 5% is used in the making of food products which contribute about 30% of the calories consumed worldwide.
Biotechnological approaches to dissect climate-resilient traits in millets and their application in crop improvement
(Elsevier B.V., 2021) Singh, Roshan Kumar; Muthamilarasan, Mehanathan; Prasad, Manoj
'Small millets' is a generic term that includes all the millets except pearl millet and sorghum. These small or minor millets constitute eleven species that are marginally cultivated and consumed worldwide. These small millets possess excellent agronomic-, climate-resilient, and nutritional traits, although they lack popularity. Small millets withstand a broad spectrum of environmental stresses and possess better water-use and nitrogen-use efficiencies. Of note, small millets are five- to seven-fold nutritionally rich in terms of protein, bioactive compounds, micro- and macro-nutrients as compared to major cereals. Irrespective of these merits, small millets have received little research attention compared to major millets and cereals. However, the knowledge generated from such studies is significant for the improvement of millets per se and for translating the information to improve major cereals through breeding and transgene-based approaches. Given this, the review enumerates the efforts invested in dissecting the climate-resilient traits in small millets and provides a roadmap for deploying the information in crop improvement of millets as well as cereals in the scenario of climate change.
Breeding and biotechnological interventions for trait improvement: status and prospects
(Springer Nature Publishing AG, 2020) Singh, Roshan Kumar; Prasad, Ashish; Muthamilarasan, Mehanathan; Parida, Swarup K.; Prasad, Manoj
Crop improvement relies on modulating the genes and genomic regions underlying key traits, either directly or indirectly. Direct approaches include overexpression, RNA interference, genome editing, etc., while breeding majorly constitutes the indirect approach. With the advent of latest tools and technologies, these strategies could hasten the improvement of crop species. Next-generation sequencing, high-throughput genotyping, precision editing, use of space technology for accelerated growth, etc. had provided a new dimension to crop improvement programmes that work towards delivering better varieties to cope up with the challenges. Also, studies have widened from understanding the response of plants to single stress to combined stress, which provides insights into the molecular mechanisms regulating tolerance to more than one stress at a given point of time. Altogether, next-generation genetics and genomics had made tremendous progress in delivering improved varieties; however, the scope still exists to expand its horizon to other species that remain underutilized. In this context, the present review systematically analyses the diferent genomics approaches that are deployed for trait discovery and improvement in major species that could serve as a roadmap for executing similar strategies in other crop species. The application, pros, and cons, and scope for improvement of each approach have been discussed with examples, and altogether, the review provides comprehensive coverage on the advances in genomics to meet the ever-growing demands for agricultural produce.
C2H2 type of zinc finger transcription factors in foxtail millet define response to abiotic stresses
(Springer, 2014) Muthamilarasan, Mehanathan; Bonthala, Venkata Suresh; Mishra, Awdhesh Kumar; Khandelwal, Rohit; Khan, Yusuf; Roy, Riti; Prasad, Manoj
C2H2 type of zinc finger transcription factors (TFs) play crucial roles in plant stress response and hormone signal transduction. Hence considering its importance, genome-wide investigation and characterization of C2H2 zinc finger proteins were performed in Arabidopsis, rice and poplar but no such study was conducted in foxtail millet which is a C4 Panicoid model crop well known for its abiotic stress tolerance. The present study identified 124 C2H2-type zinc finger TFs in foxtail millet (SiC2H2) and physically mapped them onto the genome. The gene duplication analysis revealed that SiC2H2s primarily expanded in the genome through tandem duplication. The phylogenetic tree classified these TFs into five groups (I-V). Further, miRNAs targeting SiC2H2 transcripts in foxtail millet were identified. Heat map demonstrated differential and tissue-specific expression patterns of these SiC2H2 genes. Comparative physical mapping between foxtail millet SiC2H2 genes and its orthologs of sorghum, maize and rice revealed the evolutionary relationships of C2H2 type of zinc finger TFs. The duplication and divergence data provided novel insight into the evolutionary aspects of these TFs in foxtail millet and related grass species. Expression profiling of candidate SiC2H2 genes in response to salinity, dehydration and cold stress showed differential expression pattern of these genes at different time points of stresses.
Characterization of DEAD-box family of RNA helicases in tomato provides insights into their roles in biotic and abiotic stresses
(Elsevier B.V., 2019) Pandey, Saurabh; Muthamilarasan, Mehanathan; Sharma, Namisha; Chaudhry, Vaishali; Dulani, Priya; Shweta, Shweta; Jha, Sarita; Mathur, Saloni; Prasad, Manoj
In plants, RNA helicases play significant roles in growth, development and stress response. In a previous study, a three-fold upregulation of a DEAD-box RNA helicase in a tomato cultivar tolerant to Tomato leaf curl New Delhi virus (ToLCNDV) as compared to susceptible cultivar during virus infection was shown. Given this, a comprehensive study was performed to identify the members of RNA helicase family in tomato and analyze their functional properties in response to abiotic stresses, hormone treatments and ToLCNDV infection. A total of 131 genes were identified and classified into DEAD- (42), DEAH- (38), and DExD/H-box (51) RNA helicases. Expression profiling of candidate genes in response to abiotic stresses and ToLCNDV infection in contrasting tomato cultivars suggested the putative roles of SlDEAD23 and SlDEAD35 in biotic and abiotic stresses. Heterologous overexpression of these genes in yeast enhanced the tolerance of transgenic cells to salt and cold stresses. Further, virus-induced silencing of SlDEAD35 in ToLCNDV tolerant cultivar resulted in susceptibility to virus infection, thus suggesting its involvement in tolerance mechanism. Altogether, this study provides novel insights into the structure, organization and involvement of DEAD-box RNA helicase genes in biotic and abiotic stress responses in tomato.
Comparative transcriptome profiling of two contrasting foxtail millet cultivars provides insights into molecular mechanisms underlying dehydration stress response
(Springer Nature Publishing AG, 2023) Muthamilarasan, Mehanathan; Suresh, Bonthala Venkata; Singh, Roshan Kumar; Choudhary, Pooja; Aggarwal, Pooja Rani; Prasad, Manoj
Foxtail millet (Setaria italica L.) has emerged as a model system to understand its adaptation to environmental stresses in the past decade. However, studies on understanding the molecular mechanism underlying the adaptation to dehydration stress and the regulatory network involved in the process remain elusive. In the present study, RNA-seq was performed during dehydration stress in the tolerant (IC4) and sensitive (IC41) cultivars at different time points (0, 6, and 12 h). A total of 2467 and 3318 differentially expressed genes (DEGs) were identified in IC4, and 2535 and 5572 in IC41 at 6 h and 12 h compared to control (0 h), respectively. Gene ontology (GO) analysis revealed that the DEGs were enriched in water transport, response to water deprivation, oxidative stress, amino acid and sugar transport, lipid biosynthesis, and regulation of stomatal opening. Pathway analysis suggested a significant modulation of genes involved in the metabolism of glutathione and tryptophan and biosynthesis of flavonoid, ascorbate, arginine, and proline in IC4 compared to IC41. Genes encoding for DIVARICATA, SBP family protein (teosinte glume architecture 1), and SRS family proteins (LATERAL ROOT PRIMORDIUM 1 and SHI-RELATED SEQUENCE 1) were found to be exclusively upregulated in IC4 during dehydration stress. Gene co-expression networks constructed based on the expression data showed the key modules and hubs that play critical roles during dehydration stress. Altogether, the present study has identified key genes, pathways, and regulatory modules that would serve as a base for further studies to gain insights into the dehydration-responsive molecular circuitry in foxtail millet.
Comprehensive analysis of SET domain gene family in foxtail millet identifies the putative role of SiSET14 in abiotic stress tolerance
(Nature Publishing Group, 2016) Yadav, Chandra Bhan; Muthamilarasan, Mehanathan; Dangi, Anand; Shweta, Shweta; Prasad, Manoj
SET domain-containing genes catalyse histone lysine methylation, which alters chromatin structure and regulates the transcription of genes that are involved in various developmental and physiological processes. The present study identified 53 SET domain-containing genes in C4 panicoid model, foxtail millet (Setaria italica) and the genes were physically mapped onto nine chromosomes. Phylogenetic and structural analyses classified SiSET proteins into five classes (I–V). RNA-seq derived expression profiling showed that SiSET genes were differentially expressed in four tissues namely, leaf, root, stem and spica. Expression analyses using qRT-PCR was performed for 21 SiSET genes under different abiotic stress and hormonal treatments, which showed differential expression of these genes during late phase of stress and hormonal treatments. Significant upregulation of SiSET gene was observed during cold stress, which has been confirmed by over-expressing a candidate gene, SiSET14 in yeast. Interestingly, hypermethylation was observed in gene body of highly differentially expressed genes, whereas methylation event was completely absent in their transcription start sites. This suggested the occurrence of demethylation events during various abiotic stresses, which enhance the gene expression. Altogether, the present study would serve as a base for further functional characterization of SiSET genes towards understanding their molecular roles in conferring stress tolerance.
Comprehensive genome-wide identification and expression profiling of foxtail millet [Setaria italica (L.)] miRNAs in response to abiotic stress and development of miRNA database
(Springer, 2014) Khan, Yusuf; Yadav, Amita; Bonthala, Venkata Suresh; Muthamilarasan, Mehanathan; Yadav, Chandra Bhan; Prasad, Manoj
MicroRNA (miRNA)-guided post-transcriptional regulation is an important mechanism of gene regulation during multiple biological processes including response to abiotic stresses. Foxtail millet is a model crop, which is genetically closely related to several bioenergy grasses and also known for its potential abiotic stress tolerance. Hence deciphering the role of miRNAs in regulating stress-responsive mechanism would enable imparting durable stress tolerance in both millets and bioenergy grasses. Considering this, a comprehensive genome-wide in silico analysis was performed in foxtail millet which identified 355 mature miRNAs along with their secondary structure as well as corresponding targets. Predicted miRNA targets were found to encode various DNA binding proteins, transcription factors or important functional enzymes, which could be the crucial regulators in plant abiotic stress responses. All the 355 miRNAs were physically mapped onto the foxtail millet genome and in silico tissue-specific expression for these miRNAs were studied. Comparative mapping of the 355 miRNAs between foxtail millet and other related grass species would assist miRNA studies in these genetically closely-related plants. Expression profiling was performed for eight candidate miRNAs under diverse abiotic stresses in foxtail millet, which unravelled the putative involvement of these miRNAs in stress tolerance. With an aim of providing the generated miRNA marker information to the global scientific community, a foxtail millet MiRNA Database (FmMiRNADb: http://59.163.192.91/FmMiRNADb/index.html) has also been constructed. Overall, the present study provides novel insights onto the role of miRNAs in abiotic stress tolerance and would promisingly expedite research on post-transcriptional regulation of stress-related genes in millets and bioenergy grasses.
A comprehensive study on core enzymes involved in starch metabolism in the model nutricereal, foxtail millet (Setaria italica L.)
(Elsevier B.V., 2021) Dhaka, Annvi; Muthamilarasan, Mehanathan; Prasad, Manoj
Starch biosynthesis is an important process in plants as starch serves as a source of carbon and energy. In cereals, starch is the predominant constituent of the grains that provide carbohydrates in food and feed. Given its importance, the biosynthesis and accumulation of starch have been well studied in major cereals. However, in millets, no such study provides insights into the starch biosynthesis and diversity of enzymes involved in this process. In foxtail millet (Setaria italica), we have identified and characterized six classes of enzyme-encoding genes involved in starch metabolism, viz., ADP glucose phosphorylase, starch synthase, starch branching enzyme, starch debranching enzyme, phosphorylase, and disproportionating enzyme. Analysis of gene structure, chromosomal localization, phylogenetic analysis, and study of domain composition were performed to gain insights into the structure and organization of these gene families. Further, expression profiling of these genes in two cultivars contrastingly differing in grain amylose content was performed at different seed development stages. The expression data showed spatiotemporally divergent expression patterns of the genes and pinpointed several candidate genes that could be targeted for further functional characterization to study the starch metabolism in millets as well as to improve starch content through genomics approaches.
Cutting-edge research on plant miRNAs
(Indian Academy of Sciences, 2013) Muthamilarasan, Mehanathan; Prasad, Manoj
The discovery of widespread microRNAs (miRNAs) in animals encouraged the scientists to explore miRNAs and its corresponding roles in plants, which lead to the discovery of incredible physiological functions of these novel small entities in plant systems biology. This discovery made the study on functional analysis of plant miRNA as one of the hottest research topics, globally. The year 2012 was a remarkable year of fascinating miRNA research, where numerous reports deciphering the plant miRNAs right from its origin and evolution to its diverse func- tions were published.
Development and utilization of novel SSRs in foxtail millet [Setaria italica (L.) P. Beauv.]
(John Wiley & Sons, 2013) Gupta, Sarika; Kumari, Kajal; Muthamilarasan, Mehanathan; Subramanian, Alagesan; Prasad, Manoj
Although the foxtail millet [Setaria italica (L.) P. Beauv.] is recently regarded as a model crop for studying functional genomics of biofuel grasses, its genetic improvement to some extent was limited due to the non-availability of molecular markers, particularly the microsatellite markers and the saturated genetic linkage map. Considering this, we attempted to generate a significant number of microsatellite markers in cultivar ‘Prasad’. Two hundred and fifty-six clones were sequenced to generate 41.82-kb high-quality sequences retrieved from genomic library enriched with dinucleotide repeat motifs. Microsatellites were identified in 194 (76%) of the 256 positive clones, and 64 primer pairs (pp) were successfully designed from 95 (49%) unique SSR-containing clones. The 67.4% primer designing ability, 100% PCR amplification efficiency and 45.3% polymorphic potential in the parents of F2 mapping population established the efficacy of genomic microsatellites. All the 64 microsatellite markers displayed high level of cross-species amplification (~67%) in 10 millets and non-millets species. These experimental findings suggest the utility and efficacy of SSRs in diverse genotyping applications, resolving QTLs, phylogenetic relationships and transferability in several important grass species.
Development of 5123 intron-length polymorphic markers for large-scale genotyping applications in foxtail millet
(Oxford University Press, 2014) Muthamilarasan, Mehanathan; Venkata Suresh, B.; Pandey, Garima; Kumari, Kajal; Parida, Swarup K.; Prasad, Manoj
Generating genomic resources in terms of molecular markers is imperative in molecular breeding for crop improvement. Though development and application of microsatellite markers in large-scale was reported in the model crop foxtail millet, no such large-scale study was conducted for intron-length polymorphic (ILP) markers. Considering this, we developed 5123 ILP markers, of which 4049 were physically mapped onto 9 chromosomes of foxtail millet. BLAST analysis of 5123 expressed sequence tags (ESTs) suggested the function for ∼71.5% ESTs and grouped them into 5 different functional categories. About 440 selected primer pairs representing the foxtail millet genome and the different functional groups showed high-level of cross-genera amplification at an average of ∼85% in eight millets and five non-millet species. The efficacy of the ILP markers for distinguishing the foxtail millet is demonstrated by observed heterozygosity (0.20) and Nei's average gene diversity (0.22). In silico comparative mapping of physically mapped ILP markers demonstrated substantial percentage of sequence-based orthology and syntenic relationship between foxtail millet chromosomes and sorghum (∼50%), maize (∼46%), rice (∼21%) and Brachypodium (∼21%) chromosomes. Hence, for the first time, we developed large-scale ILP markers in foxtail millet and demonstrated their utility in germplasm characterization, transferability, phylogenetics and comparative mapping studies in millets and bioenergy grass species.
Development of eSSR-markers in Setaria italica and their applicability in studying genetic diversity, cross-transferability and comparative mapping in millet and non-millet species
(PLOS, 2013) Kumari, Kajal; Muthamilarasan, Mehanathan; Misra, Gopal; Gupta, Sarika; Subramanian, Alagesan; Parida, Swarup K.; Chattopadhyay, Debasis; Prasad, Manoj
Foxtail millet (Setariaitalica L.) is a tractable experimental model crop for studying functional genomics of millets and bioenergy grasses. But the limited availability of genomic resources, particularly expressed sequence-based genic markers is significantly impeding its genetic improvement. Considering this, we attempted to develop EST-derived-SSR (eSSR) markers and utilize them in germplasm characterization, cross-genera transferability and in silico comparative mapping. From 66,027 foxtail millet EST sequences 24,828 non-redundant ESTs were deduced, representing ~16 Mb, which revealed 534 (~2%) eSSRs in 495 SSR containing ESTs at a frequency of 1/30 kb. A total of 447 pp were successfully designed, of which 327 were mapped physically onto nine chromosomes. About 106 selected primer pairs representing the foxtail millet genome showed high-level of cross-genera amplification at an average of ~88% in eight millets and four non-millet species. Broad range of genetic diversity (0.02-0.65) obtained in constructed phylogenetic tree using 40 eSSR markers demonstrated its utility in germplasm characterizations and phylogenetics. Comparative mapping of physically mapped eSSR markers showed considerable proportion of sequence-based orthology and syntenic relationship between foxtail millet chromosomes and sorghum (~68%), maize (~61%) and rice (~42%) chromosomes. Synteny analysis of eSSRs of foxtail millet, rice, maize and sorghum suggested the nested chromosome fusion frequently observed in grass genomes. Thus, for the first time we had generated large-scale eSSR markers in foxtail millet and demonstrated their utility in germplasm characterization, transferability, phylogenetics and comparative mapping studies in millets and bioenergy grass species.
Development of novel microRNA-based genetic markers in foxtail millet for genotyping applications in related grass species
(Springer, 2014) Yadav, Chandra Bhan; Muthamilarasan, Mehanathan; Pandey, Garima; Khan, Yusuf; Prasad, Manoj
DNA markers are important in molecular breeding, and, hence, considering its prominence, a variety of DNA-based molecular markers have been explored and developed for expediting crop improvement programs. microRNA (miRNA)-based molecular marker is a type of functional markers exploited predominantly in animal sciences, but reported in very few plants. Considering the efficacy, stability and transferability potential of the miRNA-based markers, the present study was conducted to develop these markers in the model crop foxtail millet. The pre-miRNA sequences of foxtail millet and other related grasses including rice, maize, wheat, sorghum and Brachypodium were retrieved and aligned for identifying the conserved regions. One hundred and seventy-six primer pairs were designed for these consensus sequences, and all these 176 miRNA-based markers were mapped onto foxtail millet genome. Of the 176 markers, 66 were chosen for further experimentations based on representing the nine chromosomes of foxtail millet and presence of highly conserved regions. All the 66 markers showed 100 % amplification in five cultivars of foxtail millet. Moreover, all the markers showed a higher level of cross-genera transferability potential with an average of ~67 % in millets and non-millet species. This is the first report on the development of novel miRNA-based markers in foxtail millet. Promisingly, these markers would serve as novel genotyping tool for various molecular breeding approaches aiming at crop improvement in millets and non-millet species.
Drought stress responses and signal transduction in plants
(Springer, 2015) Lata, Charu; Muthamilarasan, Mehanathan; Prasad, Manoj
Nature provides all necessary components for healthy growth and development of plants in the form of air, water, light, nutrients, and soil. Any imbalance in the environmental harmony may cause stress to them. Stresses encountered by plants can broadly be categorized into biotic and abiotic stresses. Biotic stresses are mainly caused by pathogens and herbivory, whereas abiotic stresses include the threat imposed by drought, salinity, and extremes of temperature, heavy metals, and pollution. Drought stress is a major cause of yield instability in crops across diverse eco-geographic regions worldwide. A variety of biochemical, molecular, and physiological changes are manifested by plants in response to drought stress. The cellular abscisic acid (ABA) concentration increases on water deficit leading to the activation of a number of stress-responsive genes and the patterns of expression of these genes are very complex, with some genes being induced early while others respond slowly. In general, drought-responsive genes respond to salt and cold stresses as well as to exogenous ABA treatment. However, there are several genes, which express themselves in an ABA-independent manner suggesting that both ABA-dependent and -independent signal transduction cascades exist for drought stress perception, response, and adaptation. Drought stress response and adaptation in plants involves an array of pathways for signal perception, transduction, gene expression and synthesis of proteins, and other stress metabolites. Drought-responsive genes can mainly be classified into two groups. First group constitutes genes whose products provide osmotolerance and protection to plants thus directly functioning in tolerance to stress, while the second group includes genes playing a role in signal transduction as well as regulation of gene expression. This chapter summarizes the complex molecular mechanisms of drought stress response and adaptation in plants, highlighting the transcriptional regulation of stress-responsive gene expression. It also focuses on the recent advances in analyzing various stress-responsive pathways with prime emphasis on ABA-dependent and -independent pathways.
Editorial: Dissecting antinutrient traits using omics approaches
(Frontiers Media S.A., 2023) Muthamilarasan, Mehanathan; Prasad, Manoj
The human population predominantly depends on plants and plant-based products for their food and nutrition. While plants are a major source of nutrients and health-promoting compounds, they also possess antinutrient factors that affect health and well-being. Global research focuses on improving important traits in plants, particularly food and nutritional security. However, few research groups work towards identifying and characterizing the antinutrient factors in food grains. These factors include cyanogen and cyanogenic glucosides, enzyme inhibitors, erucic acid, exorphins, goitrogens, lectins/hemoglutinins, lipoxygenases, nitrates, oxalate and oxalic acid, phytates, raffinose oligosaccharides, saponins, tannins, and other contextual antinutrients. Though these molecules are vital for the growth and development of plants, they pose health concerns to humans when consumed. In this context, this Research Topic was edited to collate the knowledge available on antinutrient research. The Research Topic received two research and three review articles. A comprehensive review of different antinutrients, their biosynthetic pathways, and physical and chemical methods to remove/reduce the antinutrients was provided by Duraiswamy et al.. The article provides an excellent timeline of research on this aspect and a compendium of genetic and genomic factors that underlie antinutrient biosynthesis. Also, the article provides a roadmap for using advanced genetic and genomic tools to reduce antinutrient content in food grains.