Browsing by Author "Trivedi, Prabodh Kumar"

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Broadening the epigenetic horizon of abiotic stress response in plants
(Springer Nature Publishing AG, 2024) Chhatwal, Himani; Naik, Jogindra; Pandey, Ashutosh; Trivedi, Prabodh Kumar
Plants, unlike animals, cannot move from one place to another and have to face different climatic disturbances wherever they are growing. So, they have innumerable built-in mechanisms to adapt to various abiotic stressful conditions like drought, heat, cold, and salinity. The changing environmental conditions influence the expression patterns of genes. Epigenetics involves heritable changes in DNA bases or histone proteins, which ultimately create different conformational states of chromatin. The regulatory enzymes of epigenetic modifications are grouped as writers, readers and erasers, which add, recognize and remove the epigenetic marks, respectively. Here, we provide a comprehensive overview of the mechanism of DNA methylation by the RdDM pathway, its maintenance and removal, and different histone modification categories like acetylation, methylation, phosphorylation and ubiquitination. This review further discusses in detail the crucial role these modifications play in adapting to major abiotic stresses and how plants preserve these experiences as stress memory to respond to recurring stresses. It emphasizes the role of epigenetic modifications as a crucial mechanism for building plant’s tolerance and how it can be an important research priority to improve plant growth and development under abiotic stress conditions.
COP1 mediates light-dependent regulation of flavonol biosynthesis through HY5 in Arabidopsis
(Elsevier B.V., 2021) Bhatia, Chitra; Gaddam, Subhash Reddy; Pandey, Ashutosh; Trivedi, Prabodh Kumar
Flavonols, a class of flavonoids, accumulate as protective agents in response to various stresses. Among various environmental stimuli, light is one of the factors regulating flavonol production. MYB12/11/111, members of the R2R3 MYBs family, regulates spatio-temporal flavonol accumulation in Arabidopsis. Although various studies indicate at the involvement of an E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and ELONGATED HYPOCOTYL 5 (HY5) in flavonoid biosynthesis in response to UV-B, the regulatory roles of these components under visible light are yet to be investigated. Here, we demonstrate that flavonol accumulation in Arabidopsis is light-regulated. Furthermore, our analysis suggests that MYB12 is a HY5-dependent light-inducible gene and plays a key role in the activation of the flavonol biosynthesis in response to light. Our results indicate the involvement of COP1 in the dark-dependent repression of MYB12 expression and flavonol accumulation. In addition, results also suggest that the effect of COP1 on MYB12 is indirect and is mediated through HY5, a direct transcriptional activator of the MYB12. Together these findings indicate that COP1 acts as a master negative regulator of flavonol biosynthesis in the dark.
Emerging tools and paradigm shift of gene editing in cereals, fruits, and horticultural crops for enhancing nutritional value and food security
(John Wiley & Sons, 2021) Tiwari, Manish; Trivedi, Prabodh Kumar; Pandey, Ashutosh
Gene editing using sequence‐specific nucleases, particularly CRISPR/Cas ribonucleoprotein, has drawn enormous attention in plant research in recent years. Nearly a decade ago, Cas9 protein was initially discovered for a role in adaptive immunity in bacteria. Owing to vast potential, a large number of reports came out in a short span of time, comprising the identification of Cas protein from different bacterial sources, new Cas9 variants with reduced off‐targets, multiplexing, base editing, prime editing, and RNA manipulation in plants. Studies revealed that CRISPR/Cas‐based gene editing can play a major role in ensuring food security via developing resilient commercial crops with improved yield and nutritional value. Use of the CRISPR/Cas9 system for creating mutation in genes and regulatory regions of promoter generated a number of alleles with variable phenotypes, which can serve as an excellent genetic resource in the breeding program. In this review, we provide a recent overview of state‐of‐art discoveries in the CRISPR/Cas system comprised of new Cas proteins, modifications of existing Cas9, refinements in CRISPR/Cas‐induced gene editing, applications, and outcome emphasizing on major cereals and horticultural crops. We also highlight the current global policy framework for the regulation of gene‐edited crops.
Gene pyramiding in transgenic plant development: Approaches and challenges
(Springer Nature Publishing AG, 2023) Rajput, Ruchika; Naik, Jogindra; Misra, Prashant; Trivedi, Prabodh Kumar; Pandey, Ashutosh
Climate change leads to frequent alterations in environmental factors with a reciprocal impact on crop productivity. Over the last few decades, various approaches have been used for producing more stress-tolerant and climate-flexible crops. Genetic engineering is one of the approaches used to modify multiple characters or to improve more than one agronomic trait in plants. These instances simultaneously demand simultaneous genetic manipulation of multiple genes, necessitating stacking or pyramiding of multiple genes as compared to single-gene manipulations, and the genetic engineering of plants using multiple genes is technically challenging. In the last two decades, considerable progress has been made with respect to the development and application of the methods for gene pyramiding in transgenic context. The conventional methods of gene stacking include the crossing of individual transgenic plants, co-transformation using multiple plant expression constructs, transformation with single constructs carrying multiple transgenes as well as with the constructs carrying polycistronic transgenes. These methods have been instrumental for gene stacking in several commercialized crops. The tools of targeted genome editing (ZFN, TALEN, and CRISPR) that carry out precise genetic modifications, have opened new avenues in the area of crop biotechnology for defending plants against various stresses. The present review covers the current status of biotechnological techniques used to combat biotic and abiotic stresses in crop plants and describes multiple associated challenges.
Genome wide identification of MADS box gene family in Musa balbisiana and their divergence during evolution
(Elsevier B.V., 2022) Lakhwani, Deepika; Dhar, Yogeshwar Vikarm; Singh, Shikha; Pandey, Ashutosh; Trivedi, Prabodh Kumar; Asif, Mehar Hasan
MADS box gene family is transcription factor gene family that is involved in growth and development of eukaryotes. In plants the MADS box gene family is mainly associated with floral meristem identity and flower development, apart from being involved in nearly all the phases of plant growth. The MADS box gene family has also been shown to be involved during fruit development and ripening. In this study the MADS box gene family from Musa balbisiana was identified and the divergence of this gene family between Musa balbisiana and Musa acuminata studied. A total of 97 MADS box genes were identified from the genome of Musa balbisiana. Phylogenetic analysis showed that the MbMADS box genes were categorised into type I (α and γ; the β group was not distinguishable) and type II groups (MIKCc and MIKC* and MIKCc was further divided into 13 subfamilies). The typeII group has the largest number of genes and also showed the most expansion which could be correlated with the whole genome duplications. There were significant differences in the MADS box genes from Musa acuminata and Musa balbisiana during evolution that can be correlated with different floral phenotype and fruit ripening pattern. The divergence of the MADS RIN genes in Musa balbisiana as compared to Musa acuminata might play an important role in the slow ripening of Musa balbisiana fruits.
Low temperature enhanced flavonol synthesis requires light-associated regulatory components in Arabidopsis thaliana
(Oxford University Press, 2018) Bhatia, Chitra; Pandey, Ashutosh; Gaddam, Subhash Reddy; Hoecker, Ute; Trivedi, Prabodh Kumar
Plants are continuously exposed to myriad of stresses, which lead to the formation of secondary metabolites including flavonoids. Studies suggest that low temperature exposure leads to enhanced flavonoid accumulation in Arabidopsis thaliana. In addition, flavonoid biosynthesis is regulated by light through various regulatory factors. Therefore, plant may possess the capability to integrate light and low temperature signals for survival under freezing conditions. However, detailed molecular mechanism and the regulatory factors associated with light- and low temperature- responsive flavonoid biosynthesis remain largely unknown. Here, we report a strict requirement of light for the low temperature- enhanced flavonol biosynthesis. Low temperature-induced expression of biosynthetic genes as well as flavonol accumulation was hampered in ELONGATED HYPOCOTYL (hy5) and myb11myb111myb12 triple mutants as compared to wild-type (WT) in Arabidopsis. Over-expression of AtHY5 in the hy5 mutant restored induction of gene expression and flavonol accumulation in response to low-temperature in light. Metabolite and gene expression analysis also suggests negative role of CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) in accumulation of flavonols in response to low temperature. Over-expression of AtMYB12 enhanced accumulation of flavonols under low-temperature in a light-dependent manner. Together, our analysis suggests requirement of HY5 and flavonol-specific MYB regulatory factors for low temperature-induced flavonol synthesis.
Molecular components associated with the regulation of flavonoid biosynthesis
(Elsevier B.V., 2022) Naik, Jogindra; Misra, Prashant; Trivedi, Prabodh Kumar; Pandey, Ashutosh
Flavonoids exhibit amazing structural diversity and play different roles in plants. Besides, these compounds have been associated with several health benefits in humans. Several exogenous and endogenous cues, for example, light, temperature, nutrient status, and phytohormones have been reported as modulators of biosynthesis and accumulation of flavonoids. Thus, multiple hormones and stress-related signaling pathways are involved in the regulation of gene expression associated with this pathway. The transcriptional regulators belonging to the MYB and bHLH family transcription factors are well documented as the direct regulators of the structural genes associated with flavonoid biosynthesis. Recent studies also suggest that some of these factors are regulated by molecular components involved in stress and hormone signaling pathways. Adapter proteins for transcriptional activation or repression via recruitment of co-activators and co-repressors, respectively, E2 ubiquitin ligases, miRNA processing complex, and DNA methylation/demethylation factors have been recently discovered in various plants to play key roles in fine-tuning flavonoids synthesis. In the present review, we aim to provide comprehensive information about the role of different factors in the regulation of flavonoid biosynthesis. Besides, we describe the potential upstream regulators involved in the regulation of flavonoid biosynthesis within the context of available information. To sum up, the present review furnishes an updated account of signal transduction pathways modulating the biosynthesis of flavonoids.