For biofuel purposes, large scale plantings of sweet sorghum will be done on marginal lands that are prone to environmental stresses especially drought stress, affecting the sugar yield. To be able to fully harness the potential of sweet sorghum as a biofuel crop and ensure optimum supply of biomass and ethanol, it is imperative to assess the yield and brix degree (sugar level) of sorghum cultivars under diverse environmental conditions and develop improved cultivars that are tolerant to environmental stresses. Recent studies suggest a positive correlation between drought tolerance and carbohydrate metabolism in sweet sorghum. In severe drought conditions, genotypes that are drought tolerant have been found to perform better as compared to less tolerant cultivars, as they can avoid premature senescence and perform photosynthesis for longer period of times. Therefore, it is conceivable to increase stem sugars by manipulating genes involved in drought tolerance.
|Micro-collinearity between switchgrass BAC clones and orthologous regions from Brachypodium (Bd), rice (Os), sorghum (Sb) and maize (Zm).|
Plant stresses, together with the growing population, threaten stable global food availablity. in an estimate, up to 60% of global grain production is lost because of environmental stresses. Progress in our understanding of the plant stress responses has largely relied on dissection of a limited number of generic networks that have been worked out independently. The advent and widespread availability of modern data acquisition techniques have enabled high-throughput and quantitative investigations, and we are now beginning to understand sharing of components between biotic and abiotic stress signaling pathways.Ethylene Responsive Transcription Factors (ERFs) play a vital regulatory role in variety of developmental processes and stress responses in plants. In fact, several of them (e.g. Sub1, OsERF922, BrERF4, SiERF3, GmERF3) have already been shown to confer tolerance to multiple stresses indicating that these encode multifunctional factors that play dual role in response to abiotic/biotic stresses. Therefore, ERF family genes are ideal candidates for engineering stress tolerance to multiple stresses. I performed a comprehensive phylogenomic analysis of ERFs in tomato to identify key genes regulating abiotic stress and fruit development. In collaboration with Dave Mackill, Ronald lab has isolated Submergence tolerance 1 (Sub1), which is a complex locus carrying three genes that encode putative AP2/ERF regulators. Based upon expression profiling of submergence tolerance rice variety and rice stress response interectome, we have prioritized several genes for further analysis. A Genome-scale gene network, RiceNet, can accurately predict gene function in rice and other monocot plants, and thus enables the identification of genes regulating important crop traits and their engineering. My research focus seeks to understand biology of ERFs during biotic and abiotic stress, and use this information for development of stress tolerant crops. We are trying to understand how information generated for rice can be transferred to bioenergy crop "switchgrass".
Plants are our best friends since our existence and are backbone of all the life on earth as they convert sun's energy to chemical energy that feeds the world. Thousands of years ago, human societies began to understand gathering by agriculture. In those ancient times, human beings could not read or write, even then they started a scientific discipline "Plant Domestication" i.e. genetic modification of plants to create new forms of plants, which transformed human life.
Spectacular progress has been made in genetic engineering since the recovery of the first transformed plants in the early 1980s and infect, today the manipulation of plant genome has become a core tool in plant biology. A relatively new bioscience "Plant Molecular Farming" has emerged and is gaining momentum. It involves the genetic modification of the host plant through the purposeful addition of a gene or group of genes (that hold the information for synthesizing a bio-molecule) to plant genome. For this purpose, genes of interest and nucleotide sequences required for its expression are stitched together as transcriptional units and inserted in the target genome. Plants have been engineered for variety of purposes that includes germplasm improvement and molecular farming.
Vibrio cholerae is one of the pathogens infect gastrointestinal tract and results in severe diarrhea. The pathogen colonizes intestine and secrete cholera toxin thereby causing the disease cholera. Cholera toxin B subunit (CTB) is non-toxic and is a component of a widely licensed oral cholera vaccine. For my doctoral research at DPMB, university of Delhi South Campus, I worked towards development of plant-based vaccine against V. cholera. We demonstrated for the first time that antigenic determinants from Vibrio cholerae can be produced as chimeric product, a step towards development of plant-based combinatorial vaccine. To screen useful transformants with desired level of transgene expression and copy number, a large number of transformants are required for screening and therefore, an efficient transformation protocol. I have keen interest to understand plant transformation process. Earlier, I worked to optimized an efficient Agrobacterium-mediated tomato transformation protocol. At present I am working to understand and optimize transformation process for perennial grass "Switchgrass" and M202sub1, a rice cultivar which is recalcitrant for DNA uptake. Whereas switchgrass is a potential bioenergy crop, M202sub1 is tolerant to submergence stress.