Cap Binding Complex Proteins of Indian Mustard (Brassica juncea): Cloning, Characterization and Evaluation of their Role in Abiotic Stress Tolerance

Indian economy heavily depends on agriculture which is immensely affected by various abiotic stress factors. Brassica juncea (Indian mustard) has high socio-economic importance and is used for food, fodder, condiment and oil. The soil moisture conditions after the monsoon season determines the acreage and production for the year of this rabi crop. Owing to global climatic change, yield of both irrigated and rainfed mustard will be affected in future. Hence, there is a need to study the genes empowering drought tolerance and other abiotic factors in this plant to meet the growing demand for food. Nuclear cap binding proteins CBP20 and CBP80 form a heterodimeric Cap Binding Complex (CBC) which bind to the 5’ cap structure of nascent mRNAs transcribed by RNA polymerase II. Experimental data suggests protective role of CBPs in abiotic stress tolerance, making them valuable candidates for crop improvement. This insight prompted us to assess their role in B. juncea’s plant defence against abiotic stresses. These genes have been cloned and sequences have been characterized through bioinformatics. The study led to identification of two sequences which indicate the presence of two copies of each gene. Protein sequences were analysed using various bioinformatics tools and 3D structures were examined. Gene expression analyses of both genes were carried out in different plant tissues and under abiotic stress conditions to elucidate the role of these proteins in plant growth and stress tolerance.