Institutional Publications

Permanent URI for this collectionhttps://ndkr-library.nipgr.ac.in/handle/123456789/11

Browse

Author: search.filters.author.Muthamilarasan, MehanathanSubject: search.filters.subject.Foxtail millet

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    SiHSFA2e regulated expression of SisHSP21.9 maintains chloroplast proteome integrity under high temperature stress
    (Springer Nature Publishing AG, 2022) Singh, Roshan Kumar; Muthamilarasan, Mehanathan; Prasad, Manoj
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Salinity induced differential methylation patterns in contrasting cultivars of foxtail millet (Setaria italica L.)
    (Springer, 2017) Pandey, Garima; Yadav, Chandra Bhan; Sahu, Pranav Pankaj; Muthamilarasan, Mehanathan; Prasad, Manoj
    Reduced productivity and significant yield loss are the adverse effects of environmental conditions on physiological and biochemical pathways in crop plants. In this context, understanding the epigenetic machinery underlying the tolerance traits in a naturally stress tolerant crop is imperative. Foxtail millet (Setaria italica) is known for its better tolerance to abiotic stresses compared to other cereal crops. In the present study, methylation-sensitive amplified polymorphism (MSAP) technique was used to quantify the salt-induced methylation changes in two foxtail millet cultivars contrastingly differing in their tolerance levels to salt stress. The study highlighted that the DNA methylation level was significantly reduced in tolerant cultivar compared to sensitive cultivar. A total of 86 polymorphic MSAP fragments were identified, sequenced and functionally annotated. These fragments showed sequence similarity to several genes including ABC transporter, WRKY transcription factor, serine threonine-protein phosphatase, disease resistance, oxidoreductases, cell wall-related enzymes and retrotransposon and transposase like proteins, suggesting salt stress-induced methylation in these genes. Among these, four genes were chosen for expression profiling which showed differential expression pattern between both cultivars of foxtail millet. Altogether, the study infers that salinity stress induces genome-wide DNA demethylation, which in turn, modulates expression of corresponding genes.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Reference genes for quantitative real-time PCR analysis in the model plant foxtail millet (Setaria italica L.) subjected to abiotic stress conditions
    (Springer, 2013) Kumar, Karunesh; Muthamilarasan, Mehanathan; Prasad, Manoj
    Reference genes are standards for quantifying gene expression through quantitative real-time PCR (qRT-PCR); however, the variation observed in their expression levels is the major hindrance towards realising their effective use. Hence, a systematic validation of reference genes is required to ensure proper normalization. However, no such study has been conducted in foxtail millet [Setaria italica (L.)], which has recently emerged as a model crop for genetic and genomic studies. In the present study, 8 commonly used reference genes were evaluated, including 18S ribosomal RNA, elongation factor-1α, Actin2, alpha tubulin, beta tubulin, translation factor, RNA polymerase II and adenine phosphoribosyl transferase. Expression stability of candidate internal control genes was investigated under salinity and dehydration treatments. The results obtained suggested a wide range of Ct values and variable expression of all reference genes. geNorm and NormFinder analysis had revealed that Act2 and RNA POL II are suitable reference genes for salinity stress-related studies and EF-1α and RNA POL II are appropriate internal controls for dehydration stress-related expression analyses. These qualified reference genes has also been validated for relative quantification of 14-3-3 expression analysis which demonstrated their applicability. Thus, this is the first report on selection and validation of superior reference genes for qRT-PCR in foxtail millet under different abiotic stress conditions.