Production of transgenic local rice cultivars (Oryza sativa L.) for improved drought tolerance using Agrobacterium mediated transformation.

Abstract

Rice being the staple food of middle and south India, there is an extensive research undertaken in protecting the species and improving the quality and yield. Several recombinations have been made to the rice genome to impart various qualities which lack in the pure breed. Oryza faces various natural stress, like temperature variance, high salinity, etc., drought is one of the major parameters affecting the growth and yield of the plant. Transgenic rice cultivars can be generated for drought tolerance using the Agrobacterium mediated transformations. The current work aims to impart the gene for drought tolerance in Oryza sativa L. using Agrobacterium mediated transformation. The gene targeted in this context is dehydration response element binding factors (DREB). DREB plays a major role in response to drought mediated stress. Sambha mahsuri (Indica type) and Cotton dora sannalu (Indica type) the two local cultivars have been transformed for the gene AtDREB1A under 35s CaMV promoters (pBIH binary vector) for which the vector used was Agrobacterium. The target plant tissue being used was calli. Optimization of the parameters was performed for a lethal dose of hygromycin, cefotaxime level, and acetosyringone level. PCR amplification was used for the confirmation of the transgenic (T0) species in which 23% and 18% for Sambha mahsuri and Cotton dora sannalu, respectively. Southern blotting was performed for the genomic DNA. Normal growth was shown by the T1 transgenic plants whose expression was confirmed by RT-PCR. The T1 transgenic plants showed good tolerance to drought mediated stress for a total period of one and a half week under greenhouse condition. The study can be concluded by producing a potentially successful drought resistance T1 species produced using Agrobacterium mediated transformation.