Publications of NIPGR Scientists
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Item CRISPR/dCas9-KRAB mediated transcriptional suppression of NtbHLH47 enhances tolerance to iron stress and modulates iron content in tobacco(Elsevier B.V., 2025) Alok, Anshu; Chauhan, Hanny; Rout, Biswaranjan; Pandey, Ashutosh; Singh, KashmirIron homeostasis is a multifaceted regulatory process that needs to be studied to elucidate iron distribution, uptake, and storage in plants. NtbHLH47, a homologue to AtbHLH47, is a negative regulator of iron. The current study deploys CRISPR interference-dCas9-KRAB (Krüppel-associated box) in the transcriptional suppression of NtbHLH47 and its effect on iron uptake by plants. The pHSN6I01 harbouring dCas9-KRAB and gRNA targeting NtbHHLH47 was constructed. Four gRNAs were designed, G1, G2, G3, and G4, located at + 19, + 111, + 232, and + 335 bp upstream from the ATG start codon in the promoter region of NtbHLH47. The NtbHLH47 was repressed in the developed transgenic lines of tobacco and the qRT-PCR analysis showed that target sites G1 and G2 suppressed NtbHLH47 effectively. The transgenic pHSN6I01 +G1 plants were tolerant to the elevated levels of iron, copper, zinc, and magnesium. The root Ferric chelate reductase activity of pHSN6I01 +G1 lines was reduced against wild type. The Perl staining showed high iron content in the roots of the pHSN6I01 +G1 plants. ICP-MS analysis showed increased Fe content in the roots of pHSN6I01 +G1 line suggesting that NtbHLH47 modulates it. The expression of NtbHLH38, NtbHLH100, NtbHLH101, and NtFIT was found to be upregulated in the pHSN6I01 +G1 line. This is the first report of using CRISPRi based on dCas9-KRAB in tobacco and its application in the functional validation of a gene. Using this, NtbHLH47 was transcriptionally suppressed and the generated lines expressed increased levels of iron in the roots of N. tabacum and gave insight in the iron homeostasis.Item Deciphering the complexity of terpenoid biosynthesis and its multi-level regulatory mechanism in plants(Springer Nature Publishing AG, 2024) Singh, Samar; Chhatwal, Himani; Pandey, AshutoshTerpenoids are one of the essential plant metabolites which are known to play vital roles in plants' primary growth and development including protection from biotic and abiotic stresses. They have huge structural diversity and are known to provide various health benefits, flavors, fragrances, essential oils, cosmetics, pigments, insecticides, etc. The biosynthesis of terpenoids by mevalonic acid (MVA) and methylerythritol pathway (MEP) occurs inside the cytoplasm and the chloroplast, respectively. Here, we provide a comprehensive overview of synthesis, metabolic, and regulatory pathways of terpenoid, their different classes and ecological roles. We also discuss in detail the key transcription factors (TFs) like WRKY, AP2/ERF, bHLH, MYB, NAC, and bZIP which reprogram and modulate the terpenoid pathway in plants. It also includes the post-transcriptional and post-translational modifications of these pathways. The post-transcriptional regulation by microRNA plays a critical role in the synthesis and regulation of the terpenoid. MAP kinases also regulate the stability of biosynthetic enzymes and transcription factors to regulate terpenoid biosynthesis. High-throughput sequencing technology and functional genomics have further strengthened our understanding of this pathway and associated regulatory genes which control it. As a future perspective, modifying these transcription factors via various strategies holds promise for improvement of agricultural crop plants in terms of nutritional enrichment, stress responsiveness, and resistance.Item The R2R3-MYB gene family in Cicer arietinum: genome-wide identification and expression analysis leads to functional characterization of proanthocyanidin biosynthesis regulators in the seed coat(Springer Nature Publishing AG, 2022) Rajput, Ruchika; Tyagi, Shivi; Naik, Jogindra; Pucker, Boas; Stracke, Ralf; Pandey, AshutoshChickpea (Cicer arietinum) is among the eight oldest crops and has two main types, i.e., desi and kabuli, whose most obvious difference is the color of their seeds. We show that this color difference is due to differences in proanthocyanidin content of seed coats. Using a targeted approach, we performed in silico analysis, metabolite profiling, molecular, genetic, and biochemical studies to decipher the transcriptional regulatory network involved in proanthocyanidin biosynthesis in the seed coat of C. arietinum. Based on the annotated C. arietinum reference genome sequence, we identified 119 typical CaMYB encoding genes, grouped in 32 distinct clades. Two CaR2R3-MYB transcription factors, named CaPAR1 and CaPAR2, clustering with known proanthocyanidin regulators (PARs) were identified and further analyzed. The expression of CaPAR genes correlated well with the expression of the key structural proanthocyanidin biosynthesis genes CaANR and CaLAR and with proanthocyanidin levels. Protein–protein interaction studies suggest the in vivo interaction of CaPAR1 and CaPAR2 with the bHLH-type transcription factor CaTT8. Co-transfection analyses using Arabidopsis thaliana protoplasts showed that the CaPAR proteins form a MBW complex with CaTT8 and CaTTG1, able to activate the promoters of CaANR and CaLAR in planta. Finally, transgenic expression of CaPARs in the proanthocyanidin-deficient A. thaliana mutant tt2-1 leads to complementation of the transparent testa phenotype. Taken together, our results reveal main components of the proanthocyanidin regulatory network in C. arietinum and suggest that CaPARs are relevant targets of genetic engineering toward improved agronomic traits.Item Genome-wide cis-regulatory signatures for modulation of agronomic traits as exemplified by drought yield index (DYI) in chickpea(Springer Nature Publishing AG, 2019) Sharma, Akash; Basu, Udita; Malik, Naveen; Daware, Anurag; Thakro, Virevol; Narnoliya, Laxmi; Bajaj, Deepak; Tripathi, Shailesh; Hegde, V. S.; Upadhyaya, Hari D.; Tyagi, Akhilesh K.; Parida, Swarup K.Developing functional molecular tags from the cis-regulatory sequence components of genes is vital for their deployment in efficient genetic dissection of complex quantitative traits in crop plants including chickpea. The current study identified 431,194 conserved non-coding SNP (CNSNP) from the cis-regulatory element regions of genes which were annotated on a chickpea genome. These genome-wide CNSNP marker resources are made publicly accessible through a user-friendly web-database (http://www.cnsnpcicarbase.com). The CNSNP-based quantitative trait loci (QTL) and expression QTL (eQTL) mapping and genome-wide association study (GWAS) were further integrated with global gene expression landscapes, molecular haplotyping, and DNA-protein interaction study in the association panel and recombinant inbred lines (RIL) mapping population to decode complex genetic architecture of one of the vital seed yield trait under drought stress, drought yield index (DYI), in chickpea. This delineated two constituted natural haplotypes and alleles from a histone H3 protein-coding gene and its transcriptional regulator NAC transcription factor (TF) harboring the major QTLs and trans-acting eQTL governing DYI in chickpea. The effect of CNSNPs in TF-binding cis-element of a histone H3 gene in altering the binding affinity and transcriptional activity of NAC TF based on chromatin immunoprecipitationquantitative PCR (ChIP-qPCR) assay was evident. The CNSNP-led promising molecular tags scanned will essentially have functional significance to decode transcriptional gene regulatory function and thus can drive translational genomic analysis in chickpea.Item Identifying transcription factor genes associated with yield traits in chickpea(Springer, 2017) Shimray, Philanim Wungmarong; Bajaj, Deepak; Srivastava, Rishi; Daware, Anurag; Upadhyaya, Hari D.; Kumar, Rajendra; Bharadwaj, Chellapilla; Tyagi, Akhilesh K.; Parida, Swarup K.Identification of potential transcription factor (TF) gene-derived natural SNP allelic variants regulating pod and seed yield component traits by large-scale mining and genotyping of SNPs in natural germplasm accessions coupled with high-resolution association mapping is vital for understanding the complex genetic architecture of quantitative yield traits in chickpea. In these perspectives, the current study employed a genome-wide GBS (genotyping-by-sequencing) and targeted gene amplicon resequencing-based simultaneous SNP discovery and genotyping assays, which discovered 1611 novel SNPs from 736 TF genes physically mapped on eight chromosomes and unanchored scaffolds of kabuli chickpea genome. These SNPs were structurally and functionally annotated in diverse synonymous and non-synonymous coding as well as non-coding regulatory and intronic sequence components of chickpea TF genes. A high-resolution genetic association analysis was performed by correlating the genotyping information of 1611 TF gene-based SNPs with multi-location/years field phenotyping data of six major pod and seed yield traits evaluated in a constituted association panel (326 desi and kabuli germplasm accessions) of chickpea. This essentially identified 27 TF gene-derived SNPs exhibiting significant association with six major yield traits, namely days to 50% flowering (DF), plant height (PH), branch number (BN), pod number (PN), seed number (SN) and seed weight (SW) in chickpea. These trait-associated SNPs individually and in combination explained 10–23% and 32% phenotypic variation respectively for the studied yield component traits. Interestingly, novel non-synonymous coding SNP allelic variants in five potential candidate TF genes encoding SBP (squamosal promoter binding protein), SNF2 (sucrose non-fermenting 2), GRAS [Gibberellic acid insensitive (GAI)-Repressor of GAI (RGA)-SCARECROW (SCR)], bZIP (basic leucine zipper) and LOB (lateral organ boundaries)-domain proteins associated strongly with DF, PH, BN, PN, SN and SW traits respectively were found most promising in chickpea. The functionally relevant molecular signatures (TFs and natural SNP alleles) delineated by us have potential to accelerate marker-assisted genetic enhancement by developing high pod and seed yielding cultivars of chickpea.Item CicerTransDB 1.0: a resource for expression and functional study of chickpea transcription factors(BioMed Central Ltd, 2016) Gayali, Saurabh; Acharya, Shankar; Lande, Nilesh Vikram; Pandey, Aarti; Chakraborty, Subhra; Chakraborty, NiranjanBackground: Transcription factor (TF) databases are major resource for systematic studies of TFs in specific species as well as related family members. Even though there are several publicly available multi-species databases, the information on the amount and diversity of TFs within individual species is fragmented, especially for newly sequenced genomes of non-model species of agricultural significance. Description: We constructed CicerTransDB (Cicer Transcription Factor Database), the first database of its kind, which would provide a centralized putatively complete list of TFs in a food legume, chickpea. CicerTransDB, available at www.cicertransdb.esy.es, is based on chickpea (Cicer arietinum L.) annotation v 1.0. The database is an outcome of genome-wide domain study and manual classification of TF families. This database not only provides information of the gene, but also gene ontology, domain and motif architecture. Conclusion: CicerTransDB v 1.0 comprises information of 1124 genes of chickpea and enables the user to not only search, browse and download sequences but also retrieve sequence features. CicerTransDB also provides several single click interfaces, transconnecting to various other databases to ease further analysis. Several webAPI(s) integrated in the database allow end-users direct access of data. A critical comparison of CicerTransDB with PlantTFDB (Plant Transcription Factor Database) revealed 68 novel TFs in the chickpea genome, hitherto unexplored. Database URL: http://www.cicertransdb.esy.esItem 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 Functional relationship of GBF1 with HY5 and HYH in genome-wide gene expression in Arabidopsis(Springer, 2016) Ram, Hathi; Jain, Mukesh; Singh, Aparna; Chattopadhyay, SudipTranscriptional networks play important roles in the regulation of biological processes through coordinated activation or repression of downstream target genes. Arabidopsis bZIP transcription factors, GBF1, HY5, and HYH, interact and heterodimerize with each other to form the regulatory network in photomorphogenesis. The genome-wide direct target genes of GBF1 and the roles of HY5 and HYH in controlling GBF1’s genome-wide DNA binding ability have been shown earlier. However, the GBF1 regulated genes at global scale, and how HY5 and HYH modulate GBF1-mediated genome-wide gene expression remain unknown. Here, we report the genome-wide gene expression profile in gbf1, gbf1 hy5, and gbf1 hyh mutants. Our results suggest that HY5 and HYH antagonistically regulate GBF1-mediated global gene expression. We validated the microarray analysis with independent qPCR analyses. Functional analysis of GBF1-regulated genes validates previously known roles of GBF1 in important biological processes. Furthermore, the data also highlight possible novel role of GBF1 in several other biological processes. The previous ChIP-chip results and this transcriptome data together demonstrate the complex transcriptional regulatory mechanism of these transcription factors, GBF1, HY5, and HYH, in photomorphogenesis.Item Emerging roles of auxin in abiotic stress responses(Springer, 2015) Sharma, Eshan; Sharma, Raghvendra; Borah, Pratikshya; Jain, Mukesh; Khurana, Jitendra P.Auxin is among the key growth regulators that play diverse roles in virtually all aspects of plant growth and development. Intensive investigations during the past two decades have helped in elucidation of auxin perception and signal transduction mechanisms operative in plants. In addition to its primary role in regulating plant development, several studies in recent years have provided unflinching evidence for the involvement of auxin in abiotic stress responses. Functional genomics studies and genome-wide expression analysis have revealed altered expression of auxin-responsive genes, such as Aux/IAA, GH3, SAURs, and ARFs, under abiotic stress conditions. Variations in endogenous levels of auxin at global and local levels under various abiotic stress conditions have been associated with phenotypic changes and provided intriguing evidences regarding its role in response to environmental changes. Modulation of reactive oxygen species (ROS) levels in response to exogenous auxin as well as to drought, salinity, and ABA have indicated towards a complex relationship network between auxin, ROS, and abiotic stresses in plants. The advent of recent functional genomics technologies has led to identification of several candidate genes that may modulate crosstalk between auxin and abiotic stresses. This chapter discusses auxin homeostasis, signal transduction mechanisms, and how these processes are modulated under abiotic stresses, thus emphasizing on the emerging roles of auxin as a key integrator of abiotic stress pathways and plant development.Item Mapping of functional domains and characterization of the transcription factor Cph1 that mediate morphogenesis in Candida albicans(Elsevier B.V., 2015) Maiti, Protiti; Ghorai, Priyanka; Ghosh, Sumit; Kamthan, Mohan; Tyagi, Rakesh Kumar; Datta, AsisCph1, a transcription factor of the Mitogen Activated Protein (MAP) kinase pathway, regulates morphogenesis in human fungal pathogen Candida albicans. Here, by following a systemic deletion approach, we have identified functional domains and motifs of Cph1 that are involved in transcription factor activity and cellular morphogenesis. We found that the N-terminal homeodomain is essential for the DNA binding activity; however, C-terminal domain and polyglutamine motif (PQ) are indispensable for the transcriptional activation function. Complementation analysis of the cph1Δ null mutant using various deletion derivatives revealed functional significance of the N- and C-terminal domains and PQ motif in filamentation process, chlamydospore formation and sensitivity to the cell wall interfering compounds. Genome-wide identification of the Cph1 binding site and quantitative RT-PCR transcript analysis in cph1Δ null mutant revealed that a number of genes which are associated with the filamentous growth, maintaining cell wall organization and mitochondrial function, and the genes of the pH response pathway are the transcriptional targets of Cph1. The data also suggest that Cph1 may function as a positive or negative regulator depending on the morphological state and physiological conditions. Moreover, differential expression of the upstream MAP kinase pathway genes in wild type and cph1Δ null mutant indicated the existence of a feedback regulation.
