Browsing by Author "Wardhan, Vijay"

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Calcium-dependent changes in physicochemical properties and the proteome dynamics influence dehydration responses in rice
(Elsevier B.V., 2020) Rai, Yogita; Wardhan, Vijay; Gupta, Deepti Bhushan; Chakraborty, Niranjan
The cytosolic Ca2+ ([Ca2+]cyt), in plants serves as secondary messenger during development and stress adaptive responses. While several of the components of Ca2+-signalling, especially involved in water-deficit stress or dehydration are known, the underlying mechanism of such regulations remain poorly understood. In this study, we investigated the Ca2+-mediated alleviation of dehydration stress in rice. The physicochemical indices of the rice seedlings pretreated with CaCl2, followed by dehydration treatment displayed better maintenance of relative water content (RWC) and cell membrane integrity, besides peroxide levels. CaCl2-pretreated seedling showed stimulation of antioxidants contributing to long-term survival under dehydration stress. Contrastingly, blocking of Ca2+-channels aggravated the dehydration-induced damage, suggesting a crucial role of Ca2+-signalling in stress adaptation. The cytosolic proteome profiling of CaCl2-pretreated seedlings revealed 100 distinct proteins that include 56 dehydration-responsive proteins (DRPs), presumably involved in adaptive responses. A critical screening of the proteome led to the identification of a MADS-box transcription factor family protein, designated OsMADS23. The predicted structure and nuclear localization indicated that OsMADS23 might bind to nucleic acids, suggesting its possible role in transcriptional regulation. The stimulation of stress-responsive expression of OsMADS23 by Ca2+ demonstrated its participation in Ca2+-dependent signalling. Altogether, these results indicate the Ca2+-dependent dehydration response in plants and substantiate the function of a MADS-box protein in the cross-talk of developmental and stress-responsive pathways.
Characterization of the secretome of chickpea suspension culture reveals pathway abundance and the expected and unexpected secreted proteins
(Am. Chemical Society, 2011) Gupta, Sonika; Wardhan, Vijay; Verma, Shikha; Gayali, Saurabh; Rajamani, Uma; Datta, Asis; Chakraborty, Subhra; Chakraborty, Niranjan
The secretome of an organism is defined as a set of secreted proteins that encompasses all proteins exported to the extracellular space. To better understand the chickpea secretome, we used callus culture to isolate and identify secreted proteins as a step toward determining their functions. Proteins in the extracellular media of the suspension culture were examined using SDS-PAGE and mass spectrometry (LC-MS/MS). Proteomic analysis led to the identification of 773 proteins, presumably involved in a variety of functions including metabolism, signal transduction, transport, and cell defense, in addition to maintaining redox status of extracellular space. Bioinformatic analysis confirmed 724 proteins, accounting for 94% of the identified proteins, as constituents of the secretome. Analysis of the secretome revealed the presence of several proteins of unknown function and a large number of classical and nonclassical secreted proteins. This represents the first comprehensive secretome of a legume genome, which is yet to be sequenced. Comparative analysis of the chickpea secretome with those of Medicago, Arabidopsis, and rice revealed that the majority of identified proteins are seemingly species-specific. This study demonstrates that characterization of the chickpea secretome in vitro can be used to identify secreted proteins, which has implications for systems biology research.
Chickpea transcription factor CaTLP1 interacts with protein kinases, modulates ROS accumulation and promotes ABA-mediated stomatal closure
(Nature Publishing Group, 2016) Wardhan, Vijay; Pandey, Aarti; Chakraborty, Subhra; Chakraborty, Niranjan
Tubby and Tubby-like proteins (TLPs), in mammals, play critical roles in neural development, while its function in plants is largely unknown. We previously demonstrated that the chickpea TLP, CaTLP1, participates in osmotic stress response and might be associated with ABA-dependent network. However, how CaTLP1 is connected to ABA signaling remains unclear. The CaTLP1 was found to be engaged in ABA-mediated gene expression and stomatal closure. Complementation of the yeast yap1 mutant with CaTLP1 revealed its role in ROS scavenging. Furthermore, complementation of Arabidopsis attlp2 mutant displayed enhanced stress tolerance, indicating the functional conservation of TLPs across the species. The presence of ABA-responsive element along with other motifs in the proximal promoter regions of TLPs firmly established their involvement in stress signalling pathways. The CaTLP1 promoter driven GUS expression was restricted to the vegetative organs, especially stem and rosette leaves. Global protein expression profiling of wild-type, attlp2 and complemented Arabidopsis plants revealed 95 differentially expressed proteins, presumably involved in maintaining physiological and biological processes under dehydration. Immunoprecipitation assay revealed that protein kinases are most likely to interact with CaTLP1. This study provides the first demonstration that the TLPs act as module for ABA-mediated stomatal closure possibly via interaction with protein kinase.
Comparative analysis of sequence-structure function relationship of the SUN-domain protein CaSUN1
(OMICS International, 2017) Mishra, Poonam; Wardhan, Vijay; Pandey, Aarti; Chakraborty, Subhra; Garg, Gunjan; Chakraborty, Niranjan
Sad1/UNC-84 (SUN)-domain proteins are residents of inner nuclear membrane (INM), and share structural features across species. We previously reported a highly conserved C-terminal SUN-domain family protein, designated CaSUN1, in the stress-responsive proteomic landscape of a grain legume, chickpea. In this study, we identified two other chickpea SUN proteins, CaSUN2 and CaSUN3, and performed a comparative analysis of the sequence-structure-function relationship to better understand the diversification of SUN-domain superfamily proteins. Sequence similarity across the species was investigated using multiple sequence alignment, which showed conserved patterns between CaSUN1 and the homologs. Phylogenetic analysis showed that plant SUN-domain proteins are clustered in a unique and distinct group. Using ab-initio approach, a 3D protein structure was generated and further validated using various tools including the Ramachandran plot. The results displayed 90.1% of the Ã Â and Ã Â± residues angles in the most favoured regions, suggesting a high-quality structural model for CaSUN1. Model deviation and fluctuation analysis were performed using molecular dynamics (MD) simulation of CaSUN1. The secondary structure analysis of CaSUN revealed a similarity between the structural components shared among them. CaSUN1 revealed two functional domains viz., SUN and muskelin, and the presence of kelch-repeat domain pointed out its putative role in oligomerization, while its binding affinity with different ligands indicates diverse functions. These results would not only give deeper insights into the structure-function relationships within the SUNsuperfamily proteins, but also their putative physiological roles.
Dehydration-responsive chickpea chloroplast protein, CaPDZ1, confers dehydration tolerance by improving photosynthesis
(John Wiley & Sons, 2022) Lande, Nilesh Vikram; Barua, Pragya; Gayen, Dipak; Wardhan, Vijay; Jeevaraj, Theboral; Kumar, Sunil; Chakraborty, Subhra; Chakraborty, Niranjan
The screening of a dehydration-responsive chloroplast proteome of chickpea led us to identify and investigate the functional importance of an uncharacterized protein, designated CaPDZ1. In all, we identified 14 CaPDZs, and phylogenetic analysis revealed that these belong to photosynthetic eukaryotes. Sequence analyses of CaPDZs indicated that CaPDZ1 is a unique member, which harbours a TPR domain besides a PDZ domain. The global expression analysis showed that CaPDZs are intimately associated with various stresses such as dehydration and oxidative stress along with certain phytohormone responses. The CaPDZ1-overexpressing chickpea seedlings exhibited distinct phenotypic and molecular responses, particularly increased photosystem (PS) efficiency, ETR and qP that validated its participation in PSII complex assembly and/or repair. The investigation of CaPDZ1 interacting proteins through Y2H library screening and co-IP analysis revealed the interacting partners to be PSII associated CP43, CP47, D1, D2 and STN8. These findings supported the earlier hypothesis regarding the role of direct or indirect involvement of PDZ proteins in PS assembly or repair. Moreover, the GUS-promoter analysis demonstrated the preferential expression of CaPDZ1 specifically in photosynthetic tissues. We classified CaPDZ1 as a dehydration-responsive chloroplast intrinsic protein with multi-fold abundance under dehydration stress, which may participate synergistically with other chloroplast proteins in the maintenance of the photosystem.
Genome-wide identification of the Alba gene family in plants and stress-responsive expression of the rice Alba genes
(MDPI AG, 2018) Verma, Jitendra Kumar; Wardhan, Vijay; Singh, Deepali; Chakraborty, Subhra; Chakraborty, Niranjan
Architectural proteins play key roles in genome construction and regulate the expression of many genes, albeit the modulation of genome plasticity by these proteins is largely unknown. A critical screening of the architectural proteins in five crop species, viz., Oryza sativa, Zea mays, Sorghum bicolor, Cicer arietinum, and Vitis vinifera, and in the model plant Arabidopsis thaliana along with evolutionary relevant species such as Chlamydomonas reinhardtii, Physcomitrella patens, and Amborella trichopoda, revealed 9, 20, 10, 7, 7, 6, 1, 4, and 4 Alba (acetylation lowers binding affinity) genes, respectively. A phylogenetic analysis of the genes and of their counterparts in other plant species indicated evolutionary conservation and diversification. In each group, the structural components of the genes and motifs showed significant conservation. The chromosomal location of the Alba genes of rice (OsAlba), showed an unequal distribution on 8 of its 12 chromosomes. The expression profiles of the OsAlba genes indicated a distinct tissue-specific expression in the seedling, vegetative, and reproductive stages. The quantitative real-time PCR (qRT-PCR) analysis of the OsAlba genes confirmed their stress-inducible expression under multivariate environmental conditions and phytohormone treatments. The evaluation of the regulatory elements in 68 Alba genes from the 9 species studied led to the identification of conserved motifs and overlapping microRNA (miRNA) target sites, suggesting the conservation of their function in related proteins and a divergence in their biological roles across species. The 3D structure and the prediction of putative ligands and their binding sites for OsAlba proteins offered a key insight into the structure–function relationship. These results provide a comprehensive overview of the subtle genetic diversification of the OsAlba genes, which will help in elucidating their functional role in plants.
Nuclear proteome reprogramming and acquired thermotolerance in chickpea exposed to escalating high-temperature stress
(Elsevier B.V., 2026) Pareek, Akanksha; Wardhan, Vijay; Mishra, Divya; Rathi, Divya; Khan, Iqra Nafees; Subba, Pratigya; Saxena, Harshita; Jeevaraj, Theboral; Chakraborty, Subhra; Chakraborty, Niranjan
Global chickpea (Cicer arietinum L.) production amounted to ∼17.55 MMT during 2024-2025, whose market size is valued at ∼$16.83 billion. Chickpea is highly susceptible to high-temperature stress (HTS), and its yield declines 10-15% with the rise in each degree of temperature. In this study, the HTS-responsive nuclear proteome of a thermotolerant chickpea cultivar ICC 1205 was investigated, leading to the identification of 2705 proteins, including 424 differentially regulated proteins designated as HTS-responsive (HRPs). Of these, 212 were shared between immediate (day-1) and later (day-4) stages of HTS, with 117 proteins specific to day-1 and 95 to day-4. Functional network analysis revealed a complex network of nuclear proteins involved in regulatory and stress-related functions. Detailed analysis of the proteome revealed several non-canonical proteins, suggesting HTS-responsive reprograming of the nuclear proteome landscape. The cross-species multiple abiotic stress responses recognized unique HRPs, reflecting genetic foundation that leads to crop adaptation. Comparison of protein and mRNA expression shed light on the intricate regulatory mechanisms of thermotolerance response in chickpea. The characterization of root-phototropism 2 protein (CaRPT2), a member of the NPH3 gene-family, showed significant regulations, particularly under dehydration stress and ABA treatments. Subcellular localization of CaRPT2 demonstrated its dual localization in both plasma membrane and nucleus. Analysis of physiological indices in atrpt2 loss-of function mutants in Arabidopsis demonstrated better germination rate, resilience and growth under progressive HTS, suggesting the putative role of RPT2 in regulating multiple stress-responsive genes.
Overexpression of CaTLP1, a putative transcription factor in chickpea (Cicer arietinum L.), promotes stress tolerance
(Springer, 2012) Wardhan, Vijay; Jahan, Kishwer; Gupta, Sonika; Chennareddy, Srinivasarao; Datta, Asis; Chakraborty, Subhra; Chakraborty, Niranjan
Dehydration is the most crucial environmental constraint on plant growth and development, and agricultural productivity. To understand the underlying mechanism of stress tolerance, and to identify proteins for improving such important trait, we screened the dehydration-responsive proteome of chickpea and identified a tubby-like protein, referred to as CaTLP1. The CaTLP1 was found to predominantly bind to double-stranded DNA but incapable of transcriptional activation. We investigated the gene structure and organization and demonstrated, for the first time, that CaTLP1 may be involved in osmotic stress response in plants. The transcripts are strongly expressed in vegetative tissues but weakly in reproductive tissues. CaTLP1 is upregulated by dehydration and high salinity, and by treatment with abscisic acid (ABA), suggesting that its stress-responsive function might be associated with ABA-dependent network. Overexpression of CaTLP1 in transgenic tobacco plants conferred dehydration, salinity and oxidative stress tolerance along with improved shoot and root architecture. Molecular genetic analysis showed differential expression of CaTLP1 under normal and stress condition, and its preferential expression in the nucleus might be associated with enhanced stress tolerance. Our work suggests important roles of CaTLP1 in stress response as well as in the regulation of plant development.
Secretome analysis of chickpea reveals dynamic extracellular remodeling and identifies a Bet v1- like protein, CaRRP1 that participates in stress response
(Nature Publishing Group, 2015) Gupta, Sonika; Wardhan, Vijay; Kumar, Amit; Rathi, Divya; Pandey, Aarti; Chakraborty, Subhra; Chakraborty, Niranjan
Secreted proteins maintain cell structure and biogenesis besides acting in signaling events crucial for cellular homeostasis during stress adaptation. To understand the underlying mechanism of stress-responsive secretion, the dehydration-responsive secretome was developed from suspension-cultured cells of chickpea. Cell viability of the suspension culture remained unaltered until 96 h, which gradually declined at later stages of dehydration. Proteomic analysis led to the identification of 215 differentially regulated proteins, involved in a variety of cellular functions that include metabolism, cell defence, and signal transduction suggesting their concerted role in stress adaptation. One-third of the secreted proteins were devoid of N-terminal secretion signals suggesting a non-classical secretory route. Screening of the secretome identified a leaderless Bet v 1-like protein, designated CaRRP1, the export of which was inhibited by brefeldin A. We investigated the gene structure and genomic organization and demonstrated that CaRRP1 may be involved in stress response. Its expression was positively associated with abiotic and biotic stresses. CaRRP1 could complement the aberrant growth phenotype of yeast mutant, deficient in vesicular transport, indicating a partial overlap of protein secretion and stress response. Our study provides the most comprehensive analysis of dehydration-responsive secretome and the complex metabolic network operating in plant extracellular space.