Publications of NIPGR Scientists
Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1
Browse
6 results
Search Results
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, ManojStarch 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.Item Genomic dissection and expression analysis of stress-responsive genes in C4 panicoid models, Setaria italica and Setaria viridis(Elsevier B.V., 2020) Muthamilarasan, Mehanathan; Singh, Roshan Kumar; Suresh, Bonthala Venkata; Rana, Sumi; Dulani, Priya; Prasad, ManojThe study reports the identification and expression profiling of five major classes of C4 pathway-specific genes, namely, carbonic anhydrase (CaH), phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), NADP-dependent malate dehydrogenase (MDH) and NADP-dependent malic enzyme (NADP-ME), in the model species, Setaria italica and Setaria viridis. A total of 42 and 41 genes were identified in S. italica and S. viridis, respectively. Further analysis revealed that segmental and tandem duplications have contributed to the expansion of these gene families. RNA-Seq derived expression profiles of the gene family members showed their differential expression pattern in tissues and dehydration stress. Comparative genome mapping and Ks dating provided insights into their duplication and divergence in the course of evolution. Expression profiling of candidate genes in contrasting S. italica cultivars subjected to abiotic stresses and hormone treatments showed distinct stress-specific upregulation of SiαCaH1, SiβCaH5, SiPEPC2, SiPPDK2, SiMDH8, and SiNADP-ME5 in the tolerant cultivar. Overexpression of SiNADP-ME5 in heterologous yeast system enabled the transgenic cells to survive and grow in dehydration stress conditions, which highlights the putative role of SiNADP-ME5 in conferring tolerance to dehydration stress. Altogether, the study highlights key genes that could be potential candidates for elucidating their functional roles in abiotic stress response.Item Molecular cloning and expression profiling of multiple Dof genes of Sorghum bicolor (L) Moench(Springer, 2016) Gupta, Shubhra; Arya, Gulab C.; Malviya, Neha; Bisht, Naveen C.; Yadav, DineshDNA binding with one finger (Dof) proteins represent a family of plant specific transcription factors associated with diverse biological processes, such as seed maturation and germination, phytohormone and light mediated regulation, and plant responses to biotic and abiotic stresses. In present study, a total of 21 Dof genes from Sorghum bicolor were cloned, sequenced and in silico characterized for homology search, revealing their identity to Dof like proteins. The expression profiling of SbDof genes using quantitative RT-PCR in different tissue types and also under drought and salt stresses was attempted. The SbDof genes displayed differential expression either in their transcript abundance or in their expression patterns under normal growth condition. Two of the SbDof genes namely SbDof8 and SbDof12 showed comparatively high level of transcript abundance in all the tissue types tested; whereas some of the SbDof genes showed a distinct tissue specific expression pattern. Further a total of 13 SbDof genes showed differential expression when subjected to either of the abiotic stress i.e. drought or salinity. Three of the SbDof genes namely SbDof12, SbDof19 and SbDof24 were found to be up-regulated in response to drought and salt stress. Comparative analysis of SbDof genes expression revealed existence of a complex transcriptional and functional diversity across plant growth and developmental stages.Item Rice and chickpea GDPDs are preferentially influenced by low phosphate and CaGDPD1 encodes an active glycerophosphodiester phosphodiesterase enzyme(Springer, 2016) Mehra, P.; Giri, JitenderRice and chickpea GDPD s are transcriptionally influenced by mineral deficiencies; especially, by phosphate starvation and CaGDP1 encodes an active glycerophosphodiester phosphodiesterase enzyme. Glycerophosphodiester phosphodiesterases (GDPDs) are enzymes involved in the degradation of glycerophosphodiesters into sn-glycerol-3-phosphate and corresponding alcohols. These phospholipid remodeling genes have been suggested to play important roles in phosphate homeostasis. However, comprehensive information about the role of GDPDs under low phosphate (P) and other nutrient deficiencies (N, K, Fe, Zn) in rice and chickpea is missing. Here, we identified 13 OsGDPDs and 6 CaGDPDs in rice and chickpea, respectively, and partly characterized their roles in multiple nutrient stresses. Expression profiling after 7 and 15 days of deficiency treatments revealed unique and overlapping differential expression patterns of OsGDPDs and CaGDPDs under different nutrient stresses. Principal component analysis on the expression patterns of OsGDPDs and CaGDPDs revealed their preferential role in P starvation. Some of the GDPDs were also induced by N, K, Fe and Zn deficiency in temporal manner in both crops suggesting their roles in multiple nutrient stresses. Biochemical characterization of highly responsive chickpea GDPD, CaGDPD1, confirmed its in vitro GDPD activity and revealed its optimal temperature, pH and cofactor requirements. Further, CaGDPD1 showed its accumulation in ER and endomembranes. We hereby propose CaGDPD1 and various OsGDPDs as low P responsive marker genes in chickpea and rice, respectively. Our data uphold role of GDPDs in multinutrient responses and suggest them as candidates for rice and chickpea improvement for tolerance to various nutrient deficiencies.Item Identification, characterization and expression profiling of Dicer-like, Argonaute and RNA-dependent RNA polymerase gene families in foxtail millet(Springer, 2015) Yadav, Chandra Bhan; Muthamilarasan, Mehanathan; Pandey, Garima; Prasad, ManojPost-transcriptional control of gene expression is achieved through RNA interference where the activities of Dicer-like (DCL), Argonautes (AGO) and RNA-dependent RNA polymerases (RDRs) are significant. Hence, considering the importance of DCL, AGO and RDRs, a comprehensive genome-wide analysis was performed in foxtail millet. The study identified 8 DCL, 19 AGO and 11 RDR genes. Phylogenetic and domain analysis provided interesting information on the evolutionary and structural aspects of these proteins. The orthologs of Setaria italica DCL (SiDCL), AGO (SiAGO) and RDRs (SiRDRs) were identified in sorghum, maize and rice, and the evolutionary relationships among the orthologous gene pairs were investigated. Promoter analysis of SiDCL, SiAGO and SiRDR genes revealed the presence of unique and common cis-acting elements at the upstream of respective gene sequences, which serves as binding sites for several developmental and stress-related transcription factors. In silico expression profiling using RNA-sequence data showed tissue-specific expression patterns of these genes in foxtail millet. Candidate genes representing each sub-family were chosen for expression analysis through quantitative real-time PCR (qRT-PCR) under salinity, dehydration and hormonal treatments. It revealed the differential expression pattern of candidate genes at different time points of stresses. This is the first report on genome-wide analysis of SiDCL, SiAGO and SiRDR gene families in foxtail millet, which provides basic genomic information and insights into the putative roles of these genes in abiotic stresses. The present study will serve as a base for further functional characterization of these gene families in foxtail millet and related grass species.Item 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, ManojC2H2 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.
