Research Projects

Plants face numerous biotic and abiotic challenges, including herbivores and pathogens, which can negatively impact their survival and reproduction. As a response, plants have developed a range of mechanical and chemical responses, including the glucosinolate-myrosinase system, also known as the mustard oil bomb. This system consists of glucosinolates, secondary metabolites of nitrogen and sulphur, and myrosinases, hydrolytic enzymes. Upon tissue disruption, intact glucosinolates come into contact with myrosinase, converting them to sulphate and various biologically active compounds. These degradation products are responsible for the observed biological activities of glucosinolates and may defend plants against herbivory. Six myrosinase (TGG) genes have been identified in the Arabidopsis genome, with two functional myrosinase genes expressed in leaf tissues, a pseudo gene in stamens and petals, four in root tissues, and six in flowers. However, our understanding of the type of glucosinolate degradation products in agriculturally important Brassica crops is unclear due to the presence of inherent polyploidy and complex genome architecture. An expanded repertoire of myrosinases encoding TGG genes in Brassica rapa has been identified at NIPGR. Expression analysis of these genes during plant development and in response to wounding and herbivore attack suggests a critical role of TGGs in modulating both local and systemic glucosinolate accumulation in B. rapa. Leaf and root-specific TGGs have also been identified, which needs further study for detailed biochemical and functional studies. This project is of great agricultural importance to the Indian oilseed breeding program.