Understanding the molecular and physiological mechanisms of trait diversity is crucial for crop i... more Understanding the molecular and physiological mechanisms of trait diversity is crucial for crop improvement to achieve drought adaptation. Root traits such as high biomass and/or deep rootedness are undoubtedly important drought adaptive traits. The major aim of this investigation was to functionally characterize a set of ethyl methane sulphonate (EMS)-induced rice mutants for root traits. We report the identification of a high root biomass mutant through a novel screening strategy for yield and Δ C measurements. The high root mutant (392-9-1) thus identified, had a 66% higher root biomass compared to wild type (Nagina-22). Better maintenance of leaf turgor and carbon assimilation rates resulted in lower drought susceptibility index in 392-9-1. Targeted re-sequencing revealed three non-synonymous single nucleotide variations in 392-9-1 for the genes HOX10, CITRATE SYNTHASE and ZEAXANTHIN EPOXIDASE. Segregation pattern of phenotype and mutant alleles in a single parent backcross F po...
IntroductionRice productivity is severely hampered by heat stress (HS) which induces oxidative st... more IntroductionRice productivity is severely hampered by heat stress (HS) which induces oxidative stress in this crop. This oxidative stress can be alleviated using various exogenous chemicals, including spermidine (Spd). Therefore, the present study was carried out to characterize HS components and to elucidate the role of exogenous Spd application in rice at the flowering stage. MethodsTwo contrasting rice genotypes, i.e. Nagina22 (N22) and Pusa Basmati-1121 (PB-1121) were placed in temperature tunnels and exposed to HS (38–43°C) with and without Spd (1.5 mM) foliar application during the heading stage till the end of the anthesis stage. ResultHeat stress induced the production of H2O2 and thiobarbituric acid reactive substances, which resulted in lower photosynthesis, spikelet sterility, and reduced grain yield. Interestingly, foliar application of Spd induced antioxidant enzyme activities and thus increased total antioxidant capacity resulting in higher photosynthesis, spikelet fer...
The present study was carried out during rabi 2017-18 at ICAR-Indian Agricultural Research Instit... more The present study was carried out during rabi 2017-18 at ICAR-Indian Agricultural Research Institute, New Delhi to investigate the effect of stay-green trait on grain yield in wheat under combined heat and drought stress. Two high stay green (GCP 6 and GCP 33) and two low stay green (GCP 23 and GCP 30) Recombinant Inbred Lines (RILs) of wheat along with their parents (HI1500/DBW43) were grown in field conditions under timely sown with irrigation (control) and without irrigation (drought stress), and late sown with irrigation (heat stress) and without irrigation (combined heat and drought stress). High stay-green RILs showed the reduced levels of abscisic acid and ethylene production during anthesis stage under heat, drought and combined stress conditions as compared to low stay green RILs. Furthermore, there was significantly better yield was observed in high stay-green RILs as compared to low stay-green RILs. Thus our study concludes that stay-green traits improve the yield in whea...
In recent years, the development of RNA-guided genome editing (CRISPR-Cas9 technology) has revolu... more In recent years, the development of RNA-guided genome editing (CRISPR-Cas9 technology) has revolutionized plant genome editing. Under nutrient deficiency conditions, different transcription factors and regulatory gene networks work together to maintain nutrient homeostasis. Improvement in the use efficiency of nitrogen (N), phosphorus (P) and potassium (K) is essential to ensure sustainable yield with enhanced quality and tolerance to stresses. This review outlines potential targets suitable for genome editing for understanding and improving nutrient use (NtUE) efficiency and nutrient stress tolerance. The different genome editing strategies for employing crucial negative and positive regulators are also described. Negative regulators of nutrient signalling are the potential targets for genome editing, that may improve nutrient uptake and stress signalling under resource-poor conditions. The promoter engineering by CRISPR/dead (d) Cas9 (dCas9) cytosine and adenine base editing and p...
Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited ... more Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited studies are available on protein tyrosine kinases (PTKs) that catalyze protein tyrosine phosphorylation in plants. In this study, domain analysis of the 27 annotated PTK genes in rice genome led to the identification of 18 PTKs with tyrosine kinase domain. The kinase domain of rice PTKs shared high homology with that of dual specificity kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) of Arabidopsis. In phylogenetic analysis, rice PTKs clustered with receptor-like cytoplasmic kinases-VII (RLCKs-VII) of Arabidopsis. mRNAseq analysis using Genevestigator revealed that rice PTKs except PTK9 and PTK16 express at moderate to high level in most tissues. PTK16 expression was highly abundant in panicle at flowering stage. mRNAseq data analysis led to the identification of drought, heat, salt, and submergence stress regulated PTK genes in rice. PTK14 was upregulated under all stresses. qRT-PCR analysi...
Proceedings of the National Academy of Sciences, 2010
Soil salinity limits agricultural production and is a major obstacle for feeding the growing worl... more Soil salinity limits agricultural production and is a major obstacle for feeding the growing world population. We used natural genetic variation in salt tolerance among different Arabidopsis accessions to map a major quantitative trait locus (QTL) for salt tolerance and abscisic acid (ABA) sensitivity during seed germination and early seedling growth. A recombinant inbred population derived from Landsberg erecta (L er ; salt and ABA sensitive) × Shakdara (Sha; salt and ABA resistant) was used for QTL mapping. High-resolution mapping and cloning of this QTL, Response to ABA and Salt 1 (RAS1 ), revealed that it is an ABA- and salt stress-inducible gene and encodes a previously undescribed plant-specific protein. A premature stop codon results in a truncated RAS1 protein in Sha. Reducing the expression of RAS1 by transfer-DNA insertion in Col or RNA interference in L er leads to decreased salt and ABA sensitivity, whereas overexpression of the L er allele but not the Sha allele causes ...
Proceedings of the National Academy of Sciences, 2012
MicroRNAs (miRNAs) are important for plant development and stress responses. However, factors reg... more MicroRNAs (miRNAs) are important for plant development and stress responses. However, factors regulating miRNA metabolism are not completely understood. SICKLE (SIC), a proline-rich protein critical for development and abiotic stress tolerance of Arabidopsis , was identified in this study. Loss-of-function sic -1 mutant plants exhibited a serrated, sickle-like leaf margin, reduced height, delayed flowering, and abnormal inflorescence phyllotaxy, which are common characteristics of mutants involved in miRNA biogenesis. The sic-1 mutant plants accumulated lower levels of a subset of miRNAs and transacting siRNAs but higher levels of corresponding primary miRNAs than the WT. The SIC protein colocalizes with the miRNA biogenesis component HYL1 in distinct subnuclear bodies. sic-1 mutant plants also accumulated higher levels of introns from hundreds of loci. In addition, sic-1 mutant plants are hypersensitive to chilling and salt stresses. These results suggest that SIC is a unique facto...
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 2002
Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence ... more Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence improving the cold hardiness of crop plants is an important goal in agriculture, which demands a clear understanding of cold stress signal perception and transduction. Pharmacological and biochemical evidence shows that membrane rigidification followed by cytoskeleton rearrangement, Ca 2+ influx and Ca 2+ –dependent phosphorylation are involved in cold stress signal transduction. Cold–responsive genes are regulated through C–repeat/dehydration–responsive elements (CRT/DRE) and abscisic acid (ABA)–responsive element cis elements by transacting factors C–repeat binding factors/dehydration–responsive element binding proteins (CBFs/DREBs) and basic leucine zippers (bZIPs) (SGBF1), respectively. We have carried out a forward genetic analysis using chemically mutagenized Arabidopsis plants expressing cold–responsive RD29A promoter–driven luciferase to dissect cold signal transduction. We have ...
Understanding the molecular and physiological mechanisms of trait diversity is crucial for crop i... more Understanding the molecular and physiological mechanisms of trait diversity is crucial for crop improvement to achieve drought adaptation. Root traits such as high biomass and/or deep rootedness are undoubtedly important drought adaptive traits. The major aim of this investigation was to functionally characterize a set of ethyl methane sulphonate (EMS)-induced rice mutants for root traits. We report the identification of a high root biomass mutant through a novel screening strategy for yield and Δ C measurements. The high root mutant (392-9-1) thus identified, had a 66% higher root biomass compared to wild type (Nagina-22). Better maintenance of leaf turgor and carbon assimilation rates resulted in lower drought susceptibility index in 392-9-1. Targeted re-sequencing revealed three non-synonymous single nucleotide variations in 392-9-1 for the genes HOX10, CITRATE SYNTHASE and ZEAXANTHIN EPOXIDASE. Segregation pattern of phenotype and mutant alleles in a single parent backcross F po...
IntroductionRice productivity is severely hampered by heat stress (HS) which induces oxidative st... more IntroductionRice productivity is severely hampered by heat stress (HS) which induces oxidative stress in this crop. This oxidative stress can be alleviated using various exogenous chemicals, including spermidine (Spd). Therefore, the present study was carried out to characterize HS components and to elucidate the role of exogenous Spd application in rice at the flowering stage. MethodsTwo contrasting rice genotypes, i.e. Nagina22 (N22) and Pusa Basmati-1121 (PB-1121) were placed in temperature tunnels and exposed to HS (38–43°C) with and without Spd (1.5 mM) foliar application during the heading stage till the end of the anthesis stage. ResultHeat stress induced the production of H2O2 and thiobarbituric acid reactive substances, which resulted in lower photosynthesis, spikelet sterility, and reduced grain yield. Interestingly, foliar application of Spd induced antioxidant enzyme activities and thus increased total antioxidant capacity resulting in higher photosynthesis, spikelet fer...
The present study was carried out during rabi 2017-18 at ICAR-Indian Agricultural Research Instit... more The present study was carried out during rabi 2017-18 at ICAR-Indian Agricultural Research Institute, New Delhi to investigate the effect of stay-green trait on grain yield in wheat under combined heat and drought stress. Two high stay green (GCP 6 and GCP 33) and two low stay green (GCP 23 and GCP 30) Recombinant Inbred Lines (RILs) of wheat along with their parents (HI1500/DBW43) were grown in field conditions under timely sown with irrigation (control) and without irrigation (drought stress), and late sown with irrigation (heat stress) and without irrigation (combined heat and drought stress). High stay-green RILs showed the reduced levels of abscisic acid and ethylene production during anthesis stage under heat, drought and combined stress conditions as compared to low stay green RILs. Furthermore, there was significantly better yield was observed in high stay-green RILs as compared to low stay-green RILs. Thus our study concludes that stay-green traits improve the yield in whea...
In recent years, the development of RNA-guided genome editing (CRISPR-Cas9 technology) has revolu... more In recent years, the development of RNA-guided genome editing (CRISPR-Cas9 technology) has revolutionized plant genome editing. Under nutrient deficiency conditions, different transcription factors and regulatory gene networks work together to maintain nutrient homeostasis. Improvement in the use efficiency of nitrogen (N), phosphorus (P) and potassium (K) is essential to ensure sustainable yield with enhanced quality and tolerance to stresses. This review outlines potential targets suitable for genome editing for understanding and improving nutrient use (NtUE) efficiency and nutrient stress tolerance. The different genome editing strategies for employing crucial negative and positive regulators are also described. Negative regulators of nutrient signalling are the potential targets for genome editing, that may improve nutrient uptake and stress signalling under resource-poor conditions. The promoter engineering by CRISPR/dead (d) Cas9 (dCas9) cytosine and adenine base editing and p...
Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited ... more Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited studies are available on protein tyrosine kinases (PTKs) that catalyze protein tyrosine phosphorylation in plants. In this study, domain analysis of the 27 annotated PTK genes in rice genome led to the identification of 18 PTKs with tyrosine kinase domain. The kinase domain of rice PTKs shared high homology with that of dual specificity kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) of Arabidopsis. In phylogenetic analysis, rice PTKs clustered with receptor-like cytoplasmic kinases-VII (RLCKs-VII) of Arabidopsis. mRNAseq analysis using Genevestigator revealed that rice PTKs except PTK9 and PTK16 express at moderate to high level in most tissues. PTK16 expression was highly abundant in panicle at flowering stage. mRNAseq data analysis led to the identification of drought, heat, salt, and submergence stress regulated PTK genes in rice. PTK14 was upregulated under all stresses. qRT-PCR analysi...
Proceedings of the National Academy of Sciences, 2010
Soil salinity limits agricultural production and is a major obstacle for feeding the growing worl... more Soil salinity limits agricultural production and is a major obstacle for feeding the growing world population. We used natural genetic variation in salt tolerance among different Arabidopsis accessions to map a major quantitative trait locus (QTL) for salt tolerance and abscisic acid (ABA) sensitivity during seed germination and early seedling growth. A recombinant inbred population derived from Landsberg erecta (L er ; salt and ABA sensitive) × Shakdara (Sha; salt and ABA resistant) was used for QTL mapping. High-resolution mapping and cloning of this QTL, Response to ABA and Salt 1 (RAS1 ), revealed that it is an ABA- and salt stress-inducible gene and encodes a previously undescribed plant-specific protein. A premature stop codon results in a truncated RAS1 protein in Sha. Reducing the expression of RAS1 by transfer-DNA insertion in Col or RNA interference in L er leads to decreased salt and ABA sensitivity, whereas overexpression of the L er allele but not the Sha allele causes ...
Proceedings of the National Academy of Sciences, 2012
MicroRNAs (miRNAs) are important for plant development and stress responses. However, factors reg... more MicroRNAs (miRNAs) are important for plant development and stress responses. However, factors regulating miRNA metabolism are not completely understood. SICKLE (SIC), a proline-rich protein critical for development and abiotic stress tolerance of Arabidopsis , was identified in this study. Loss-of-function sic -1 mutant plants exhibited a serrated, sickle-like leaf margin, reduced height, delayed flowering, and abnormal inflorescence phyllotaxy, which are common characteristics of mutants involved in miRNA biogenesis. The sic-1 mutant plants accumulated lower levels of a subset of miRNAs and transacting siRNAs but higher levels of corresponding primary miRNAs than the WT. The SIC protein colocalizes with the miRNA biogenesis component HYL1 in distinct subnuclear bodies. sic-1 mutant plants also accumulated higher levels of introns from hundreds of loci. In addition, sic-1 mutant plants are hypersensitive to chilling and salt stresses. These results suggest that SIC is a unique facto...
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 2002
Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence ... more Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence improving the cold hardiness of crop plants is an important goal in agriculture, which demands a clear understanding of cold stress signal perception and transduction. Pharmacological and biochemical evidence shows that membrane rigidification followed by cytoskeleton rearrangement, Ca 2+ influx and Ca 2+ –dependent phosphorylation are involved in cold stress signal transduction. Cold–responsive genes are regulated through C–repeat/dehydration–responsive elements (CRT/DRE) and abscisic acid (ABA)–responsive element cis elements by transacting factors C–repeat binding factors/dehydration–responsive element binding proteins (CBFs/DREBs) and basic leucine zippers (bZIPs) (SGBF1), respectively. We have carried out a forward genetic analysis using chemically mutagenized Arabidopsis plants expressing cold–responsive RD29A promoter–driven luciferase to dissect cold signal transduction. We have ...
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Papers by Viswanathan Chinnusamy