Functional Genomics Lab

Molecular characterization and functional analysis of defence responsive genes in medicinal plants: Plants are exposed to a variety of biotic and abiotic stresses. To survive under these challenges, plants have developed elaborate signal transduction mechanisms to counter act against the external signals and establish cellular responses. Plant pathogen interaction is highly complex due to their differential recognizing abilities and varied resistant mechanism. Turmeric is a plant of great medicinal and economic significance. However, its productivity is not upto the demand owing to various biotic and abiotic stress incidences. Therefore, we are trying to clone and characterize the genes controlling signaling modules as well as plant R-genes to get better insights about the organization, function and modulation of defense response and performances underlying signal transduction pathway of asexually reproducing plant attacked by pathogens.

Molecular and physiological characterization of MAPK kinases in asexually reproducing plants: The fact that most of the disease resistance genes contain kinase domains or have kinase activity suggest a key role for protein phosphorylation in perception of pathogen signals and the subsequent R-gene mediated signaling pathways in plants. Although several families of proteins may orchestrate protein phosphorylation, the mitogen activated protein kinase (MAPK) cascade acts as part of major transduction pathway that transfers the extracellular stimuli into an intracellular response. They are functionally linked and operate as an important network for amplifying, integrating, and channelling a broad spectrum of signals from the upstream receptors to the downstream cellular effectors, leading to an adaptive stress response at cellular and organismal levels. However, there is no information about the role of MAPK genes in the stress regulation of asexually reproducing plants in general and turmeric in particular. Although MAPK genes have been cloned from diverse plants, current studies give priority to cDNA cloning, analysis of expression, or kinase activity under various conditions, whereas the functions of the isolated MAPK genes have been less well characterized. A candidate gene approach based on polymerase chain reaction (PCR) with degenerate primers designed according to conserved is being used to isolate and characterize putative stress responsive MAPK clone in these lower monocots.

Development of sex markers and characterization of sex linked genes in Cucurbitaceous plants: Understanding the factors behind sex expression has immense importance both in basic and applied research. The sex determination has evolved exceedingly rarely in plants.  Although there is no evidence that all organisms with separate sexes acquire morphologically distinct sex chromosomes, theory predicts that the assortative accumulation of sex-determining and sexually antagonistic genes results in the physical differentiation of the two sex chromosomes. To gain insight into such genes, it will be necessary to sequence a long sex-linked region to study substitution behavior and visualize its physical placement. The first step towards this goal is to develop markers that could detect the presence of such genes in the sex chromosomes. Coccinia, a dioecious genus of the family cucurbitaceae, with an established sex-determination system is being used as a model system towards early identification of sex and characterization of sex linked genes.