Browsing by Author "Ankit, Ankit"

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Genome-wide identification and molecular characterization of core ABA signaling components under abiotic stresses and during development in chickpea
(Springer Nature Publishing AG, 2025) Kamali, Saravanappriyan; Sonkar, Kamankshi; Ankit, Ankit; Deepika, Deepika; Sharma, Ankita; Singh, Amarjeet
Abscisic acid (ABA) signaling is vital for plant's response to abiotic stresses and development. Core components of ABA signaling include ABA receptors PYR/PYL/RCAR, group-A PP2Cs (PP2C-As) and SnRK2 serine/threonine kinases. These have been well studied in Arabidopsis, but their knowledge in the legume crop chickpea is missing. Here, we identified 8 PYLs, 11 PP2C-As and 13 SnRK2s genes in the chickpea genome. Gene duplication events have been found to drive their evolution and expansion in chickpea. Protein homology modeling revealed three-dimensional structure, and arrangements of α-helix, β-sheets and p-loops in respective families. In-planta subcellular localization analysis revealed that CaPYL3 and CaPYL5 proteins were localized at the plasma membrane, and CaPP2CA-1 and CaSnRK2.7 were localized in the cytoplasm and the nucleus. RNA sequencing data analysis indicated the regulatory role of CaPYLs, CaPP2C-As and CaSnRK2s in developmental stages particularly, stages of early embryogenesis to seed maturity. Through RT-qPCR analysis drought, salt and ABA responsive CaPYL, CaPP2C-A and CaSnRK2 genes, which might regulate abiotic stress response in chickpea were identified. Importantly, key genes like CaPYL4, CaPP2C-A4, CaPP2C-A11 and CaSnRK2.9 with overlapping expression in drought, ABA and seed development were identified, which might determine chickpea crop yield. In-silico interaction analysis revealed specific and overlapping interaction among ABA signaling proteins indicating their functional relevance. Overall, core ABA signaling components are crucial for abiotic stress tolerance and development in chickpea. These genes will be functionally validated in the future and will be utilized to generate abiotic stress resilience and high-yielding chickpea varieties.
Genomic & structural diversity and functional role of potassium (K+) transport proteins in plants
(Elsevier B.V., 2022) Ankit, Ankit; Kamali, Saravanappriyan; Singh, Amarjeet
Potassium (K+) is an essential macronutrient for plant growth and productivity. It is the most abundant cation in plants and is involved in various cellular processes. Variable K+ availability is sensed by plant roots, consequently K+ transport proteins are activated to optimize K+ uptake. In addition to K+ uptake and translocation these proteins are involved in other important physiological processes like transmembrane voltage regulation, polar auxin transport, maintenance of Na+/K+ ratio and stomata movement during abiotic stress responses. K+ transport proteins display tremendous genomic and structural diversity in plants. Their key structural features, such as transmembrane domains, N-terminal domains, C-terminal domains and loops determine their ability of K+ uptake and transport and thus, provide functional diversity. Most K+ transporters are regulated at transcriptional and post-translational levels. Genetic manipulation of key K+ transporters/channels could be a prominent strategy for improving K+ utilization efficiency (KUE) in plants. This review discusses the genomic and structural diversity of various K+ transport proteins in plants. Also, an update on the function of K+ transport proteins and their regulatory mechanism in response to variable K+ availability, in improving KUE, biotic and abiotic stresses is provided.
Genomic, structural, and molecular analysis of calmodulin-binding transcriptional activators (CAMTAs) suggests their role in plant development and abiotic stress tolerance in chickpea
(Elsevier B.V., 2025) Sonkar, Kamankshi; Kamali, Saravanappriyan; Kumar, Atul; Deepika, Deepika; Ankit, Ankit; Singh, Amarjeet
The calmodulin-binding transcriptional activator (CAMTA) transcription factors regulate the expression of target genes in Ca2 + dependent cellular functions. CAMTAs are known to regulate biotic and abiotic stress tolerance, and development in plants. CAMTA family has been characterized in Arabidopsis, it is yet to be explored in the legume plant chickpea. Here, we have identified and characterized the chickpea CAMTA family. Total seven CAMTA genes (CaCAMTA1–7) were identified in chickpea. Gene and domain structure analyses suggested that CAMTAs are structurally conserved. The phylogenetic analysis demarcated CaCAMTAs into three groups namely; group I, II and III, and indicated that CaCAMTAs have co-evolved in dicot leguminous plants whereas, they have divergent evolution in monocots. Protein homology modeling revealed their three-dimensional structure, and composition & conformations of α-helix, β-sheets and p-loops. Subcellular localization showed that CaCAMTA4 was localized both, in the nucleus and the cytosol whereas, CaCAMTA5 was localized in the nucleus. CaCAMTA promoters contain various cis-regulatory elements related to abiotic stresses and plant development. Expression profiling using RNA-seq data revealed differential expression of CaCAMTAs during various stages of plant development. RT-qPCR expression analysis showed that most CaCAMTA genes are drought, salt, and ABA responsive, suggesting their role in abiotic stress tolerance in chickpea. Moreover, CaCAMTA regulon was identified based on the presence of CAMTA binding motif (CGCG box) in the promoters of target genes, and in-silico interaction analysis of TF and putative targets. Overall, CaCAMTAs are crucial for abiotic stress tolerance and plant development in chickpea. Key CaCAMTA genes will be functionally characterized, and will be exploited for developing stress tolerant chickpea varieties.
Jasmonic acid biosynthesis pathway and its functional role in plants
(Elsevier B.V., 2023) Ankit, Ankit; Kamali, Saravanappriyan; Singh, Amarjeet
Plants encounter various abiotic and biotic stresses including drought, heat, cold, salinity, osmotic stress, fungal infection, herbivore attacks in their natural habitat. In these unavoidable circumstances various phytohormones play crucial roles in regulating plant growth and development (Khan et al., 2019, 2020a, 2020b; Nazir et al., 2019, 2021, 2022; Poo´r et al., 2021). Jasmonic acid (JA) is a lipid-derived phytohormone which acts as a signal as well as regulator in various physiological processes and stress conditions. Methyl ester of JA (MeJA) is the first active jasmonate which was detected and isolated as an odorant from Jasminium grandiflorum flowers (Demole et al., 1962). Among the conjugates of JA, JA-Ile is the most biologically active form (Fonseca et al., 2009). Recently, cis-(1)-12- oxophytodienoic acid (OPDA) an intermediate in the lipoxygenases (LOX) pathway for JA biosynthesis has been shown to be functional signaling molecule instead of JA in lower plants, such as Marchantia polymorpha (liverworts), Physcomitrella patens (moss) and Selaginella martensii (spikemoss) (Ogorodnikova et al., 2015; Stumpe et al., 2010; Yamamoto et al., 2015). Apart from bryophytes, fungus species such as Fusarium oxysporum have JA and/or JA-Ile conjugate (Miersch et al., 1999). Although, JA and its derivatives are distributed among bryophytes and fungi, most of the homologs of JA biosynthesis enzymes are present in major lineages of land plants (Han, 2017). In last decade, studies have been performed in both monocotyledons as well as dicotyledons plants to better understand the JA biosynthesis mechanism. In Arabidopsis, JA biosynthesis mainly occurs in chloroplast, peroxisome and cytoplasm (Ruan et al., 2019). In chloroplast, OPDA is synthesized from unsaturated fatty acid α-linolenic acid (α-LeA) derived from the chloroplast membrane, followed by its conversion into JA in peroxisome. The conversion of JA into different functional and structural metabolites takes place in the cytoplasm. JA and its other derivatives like MeJA and JA-Ile are collectively known as jasmonates.
Morphophysiological and transcriptome analysis reveal that reprogramming of metabolism, phytohormones and root development pathways governs the potassium (K+) deficiency response in two contrasting chickpea cultivars
(Frontiers Media S.A., 2023) Ankit, Ankit; Singh, Ajeet; Kumar, Shailesh; Singh, Amarjeet
Potassium (K+) is an essential macronutrient for plant growth and development. K+ deficiency hampers important plant processes, such as enzyme activation, protein synthesis, photosynthesis and stomata movement. Molecular mechanism of K+ deficiency tolerance has been partly understood in model plants Arabidopsis, but its knowledge in legume crop chickpea is missing. Here, morphophysiological analysis revealed that among five high yielding desi chickpea cultivars, PUSA362 shows stunted plant growth, reduced primary root growth and low K+ content under K+ deficiency. In contrast, PUSA372 had negligible effect on these parameters suggesting that PUSA362 is K+ deficiency sensitive and PUSA372 is a K+ deficiency tolerant chickpea cultivar. RNA-seq based transcriptome analysis under K+ deficiency revealed a total of 820 differential expressed genes (DEG's) in PUSA362 and 682 DEGs in PUSA372. These DEGs belongs to different functional categories, such as plant metabolism, signal transduction components, transcription factors, ion/nutrient transporters, phytohormone biosynthesis and signalling, and root growth and development. RNA-seq expression of randomly selected 16 DEGs was validated by RT-qPCR. Out of 16 genes, 13 showed expression pattern similar to RNA-seq expression, that verified the RNA-seq expression data. Total 258 and 159 genes were exclusively up-regulated, and 386 and 347 genes were down-regulated, respectively in PUSA362 and PUSA372. 14 DEGs showed contrasting expression pattern as they were up-regulated in PUSA362 and down-regulated in PUSA372. These include somatic embryogenesis receptor-like kinase 1, thaumatin-like protein, ferric reduction oxidase 2 and transcription factor bHLH93. Nine genes which were down-regulated in PUSA362 found to be up-regulated in PUSA372, including glutathione S-transferase like, putative calmodulin-like 19, high affinity nitrate transporter 2.4 and ERF17-like protein. Some important carbohydrate metabolism related genes, like fructose-1,6-bisphosphatase and sucrose synthase, and root growth related Expansin gene were exclusively down-regulated, while an ethylene biosynthesis gene 1-aminocyclopropane-1-carboxylate oxidase 1 (ACO1) was up-regulated in PUSA362. Interplay of these and several other genes related to hormones (auxin, cytokinin, GA etc.), signal transduction components (like CBLs and CIPKs), ion transporters and transcription factors might underlie the contrasting response of two chickpea cultivars to K+ deficiency. In future, some of these key genes will be utilized in genetic engineering and breeding programs for developing chickpea cultivars with improved K+ use efficiency (KUE) and K+ deficiency tolerance traits.