Effects of water stress on biochemical character and transcription factors expression in rice (Oryza sativa L.)

In this study, the effect of water stress at vegetative stages on biochemical traits, and expression of genes coding for transcription factors OsMYB2, and OsLEA were investigated in two Indian rice cultivars; Nagina22 and Pusa Basmati 1. Activity of proline and chlorophyll content were studied and also found to be different among the rice cultivars in both the conditions. Rice cv. Nagina22 was more efficient in maintaining high Proline content on exposure to water stress as compared Pusa Basmati 1. The Chlorophyll content in both the rice variety decreased significantly under water stress condition as compared to control condition. The expression results demonstrated that there was upregulation of OsMYB2 gene in rice varieties under water stress condition as comparison to control condition. The expression analysis of this gene shows 64 fold upregulation in Nagina 22, however in Pusa Basmati 1 it shows only 8 fold upregulation under water stress condition as comparison to control condition. The expression of OsLEA gene also upregulated in all varieties of rice under water stress condition as comparison to control condition. Biochemical and expression analysis revealed that studied biochemical analysis along with transcription factors OsMYB2 may play an essential role in tolerance to water stress, and therefore may be a useful candidate in developing transgenic plants with improved water stress tolerance.