Browsing by Author "Chinnusamy, Viswanathan"

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A CRISPR-Cas9 library to target putative redundant gene sets facilitates their functional exploration in grain development in rice
(Springer Nature Publishing AG, 2025) Yadav, Banita; Sardar, Shaswati; Yadav, Anil; Kumari, Annapurna; Gautam, Mohini; Mandlik, Rushil; Arora, Simran; Kumar, Shailesh; Jewaria, Pawan Kumar; Sonah, Humira; Deshmukh, Rupesh; Chinnusamy, Viswanathan; Ram, Hasthi
Advent of CRISPR-Cas9 library approach has revolutionized the field of high throughput targeted mutagenesis in plants. By identifying an sgRNA spacer that can target multiple paralogous genes in a genome, higher-order knockout plants can be developed. Using this concept, we developed ten CRISPR-Cas9 pool libraries and generated higher-order knockout plants in rice. Towards this, firstly we identified genome-wide sets of genes which are co-expressed and have high sequence similarity and can be targeted by a single sgRNA. Based on the expression pattern, these genes were divided into ten groups, and subsequently ten CRISPR-Cas9 plasmid libraries were developed. One such library designed against seed-expressed genes was transformed into rice and higher-order knockout plants were developed. Genotyping revealed that around 90% T0 plants had editing, and among the edited plants majority of them were higher-order knockouts. Phenotypic analysis in the next generation discovered functions of several seed specific genes in grain length, width, number and 100-grain weight. By analyzing single and double mutants for two Agenet domain-containing proteins, we have discovered an epistatic interaction between them for grain development. Further application of our approach will help to uncover hidden functions of the targeted genes and accelerate functional genomics research in rice. The CRISPR-Cas9 library is a useful approach to generate higher-order knockout mutants and identify functions of the targeted genes in rice.
Gene network modules associated with abiotic stress response in tolerant rice genotypes identified by transcriptome meta-analysis
(Springer Nature Publishing AG, 2020) Smita, Shuchi; Katiyar, Amit; Lenka, Sangram Keshari; Dalal, Monika; Kumar, Amish; Mahtha, Sanjeet Kumar; Yadav, Gitanjali; Chinnusamy, Viswanathan; Pandey, Dev Mani; Bansal, Kailash Chander
Abiotic stress tolerance is a complex trait regulated by multiple genes and gene networks in plants. A range of abiotic stresses are known to limit rice productivity. Meta-transcriptomics has emerged as a powerful approach to decipher stress-associated molecular network in model crops. However, retaining specificity of gene expression in tolerant and susceptible genotypes during meta-transcriptome analysis is important for understanding genotype-dependent stress tolerance mechanisms. Addressing this aspect, we describe here “abiotic stress tolerant” (ASTR) genes and networks specifically and differentially expressing in tolerant rice genotypes in response to different abiotic stress conditions. We identified 6,956 ASTR genes, key hub regulatory genes, transcription factors, and functional modules having significant association with abiotic stress–related ontologies and cis-motifs. Out of the 6956 ASTR genes, 73 were co-located within the boundary of previously identified abiotic stress trait–related quantitative trait loci. Functional annotation of 14 uncharacterized ASTR genes is proposed using multiple computational methods. Around 65% of the top ASTR genes were found to be differentially expressed in at least one of the tolerant genotypes under different stress conditions (cold, salt, drought, or heat) from publicly available RNAseq data comparison. The candidate ASTR genes specifically associated with tolerance could be utilized for engineering rice and possibly other crops for broad-spectrum tolerance to abiotic stresses.