Executive Summary : | Metals and metalloid ions are natural components of our planet, but their high concentrations can cause toxicity in various life forms, including microorganisms, plants, animals, and humans. Heavy metals like cadmium and arsenic are carcinogenic and can disrupt DNA synthesis and repair. They are highly toxic and pose a significant threat to soil, food-chain, and drinking water. Arsenic and cadmium are particularly toxic and can transfer from soil to plant tissues, such as grain. Phytotoxicity varies with the concentration of these elements in soil and plant species and cultivars. Some plant species or cultivars have developed tolerance to heavy metals, altering gene expression levels to cope with stress. Brassica juncea, a fast-growing high-biomass plant, can store high concentrations of heavy metals in its organs. Tolerance to these metals is due to up-regulation of transporter genes and genes of hormonal pathways like auxin and jasmonate biosynthesis. Endogenous small RNAs, such as miRNAs and siRNAs, are involved in regulating plant developmental pathways and stress responses. MicroRNAs are small, non-coding regulatory RNA sequences that negatively regulate gene expression at the post-transcriptional level. This research proposal aims to identify Cd and As responsive miRNAs of Indian mustard, target prediction of identified miRNAs using computational approaches, and validation of selected miRNAs in Indian mustard genotypes. |