Browsing by Author "Singh, Anil K."

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Seedling-stage salinity tolerance in rice: decoding the role of transcription factors
(John Wiley & Sons, 2022) Tiwari, Shalini; Nutan, Kamlesh Kant; Deshmukh, Rupesh; Sarsu, Fatma; Gupta, Kapuganti Jagadis; Singh, Anil K.; Singla-Pareek, Sneh L.; Pareek, Ashwani
Rice is an important staple food crop that feeds over half of the human population, particularly in developing countries. Increasing salinity is a major challenge for continuing rice production. Though rice is affected by salinity at all the developmental stages, it is most sensitive at the early seedling stage. The yield thus depends on how many seedlings can withstand saline water at the stage of transplantation, especially in coastal farms. The rapid development of ‘omics’ approaches has assisted researchers in identifying biological molecules that are responsive to salt stress. Several salinity-responsive quantitative trait loci (QTL) contributing to salinity tolerance have been identified and validated, making it essential to narrow down the search for the key genes within QTLs. Owing to the impressive progress of molecular tools, it is now clear that the response of plants towards salinity is highly complex, involving multiple genes, with a specific role assigned to the repertoire of transcription factors. Targeting the transcription factors for improving salinity tolerance can have an inbuilt advantage of influencing multiple downstream genes, which in turn can contribute towards tolerance to multiple stresses. This is the first comparative study for TF-driven salinity tolerance in contrasting rice cultivars at the seedling stage that shows how tolerant genotypes behave differently than sensitive ones in terms of stress tolerance. Understanding the complexity of salt-responsive transcription factor networks at the seedling stage will be helpful to alleviate crop resilience and prevent crop damage at an early growth stage in rice.
Unique miRNome during anthesis in drought-tolerant indica rice var. Nagina 22
(Springer, 2015) Kansal, Shivani; Devi, Roseeta M.; Balyan, Sonia C.; Arora, Mukesh K.; Singh, Anil K.; Mathur, Saloni; Raghuvanshi, Saurabh
MAIN CONCLUSION: Drought-tolerant rice variety, Nagina 22 (N22), has a unique spikelet miRNome during anthesis stage drought as well as transition from heading to anthesis. Molecular characterization of genetic diversity of rice is essential to understand the evolution and molecular basis of various agronomically important traits such as drought tolerance. miRNAs play an important role in regulating plant development as well as stress response such as drought. In this study, we characterized the yet unexplored dynamics of the spikelet miRNA population during developmental transition from 'heading' to 'anthesis' as well as anthesis stage drought stress in a drought-tolerant indica rice variety, N22. A significant proportion of miRNA population (~20 %) in N22 spikelets is modulated during transition from heading to anthesis indicating a unique miRNome at anthesis, a developmental stage highly sensitive to stress (drought/heat). Based on the analysis of degradome data, majority of differentially regulated miRNAs appear to regulate transcription factors, some of which are implicated in regulation of development and fertilization. Similarly, drought during anthesis leads to a global change in miRNA expression pattern including those which regulate ROS homeostasis. It was possible to identify several miRNAs that were not reported to be drought responsive in earlier studies. Interestingly, a significant proportion of the drought-regulated miRNAs co-localize within QTLs related to drought tolerance and associated traits. Comparison of the expression profiles between N22 and Pusa Basmati 1 (drought sensitive) identified miRNAs with variety-specific expression patterns during phase transition (miR164, miR396, miR812, and miR1881) as well as drought stress (miR1881) indicating an evolution of a distinct and variety-specific regulatory mechanism. The promoters of these miRNAs contain LREs (light-responsive elements) and are induced by dark treatment. It was also possible to identify 4 novel miRNAs including an intronic miRNA that was conserved in both rice varieties.