Identification of genes for seed germination and dormancy in Rice

Endogenous ABA level in seeds have a positive correlation with dormancy and negative correlation with seed germination. The optimum level of ABA is maintained by the balance between biosynthesis and catabolism. ABA catabolism is mainly carried out by 8'-hydroxylation pathway in plants. In Arabidopsis, a Cytochrome P450 family namely CYP707A was found to be involved in the process of ABA catabolism and the present study was conducted to identify the members of CYP707A family in rice and the candidate P450 involved in ABA accumulation in developing seeds. Pattern of ABA accumulation was studied and it reaches maximum at 25 DAF. Semi-quantitative RT-PCR analysis revealed that the expression pattern of the rice homolog OsCYP707A5 is closely associated with ABA levels in the maturing rice seeds