Abstract:

In order to study the effects of OsBAK1P,a precursor of Brassinosteroid insensitivity 1-associated receptor kinase 1,on the agronomic characteristics of rice.A target sequence fragment with a CDS fragment size of 651 bp was amplified from the rice panicle cDNA using the Zhonghua 11 japonica rice variety as the material according to the specific primers designed by the gene;the PTCK303-OsBAK1P overexpression vector and the PTCK303-OsBAK1P RNA interference vector were successfully constructed by restriction enzyme digestion and ligation methods;the Agrobacterium tumefaciens EHA105 strain was transformed into the correct expression vector plasmid,and the positive Agrobacterium tumefaciens clones were screened out by using CDS amplification primers;the callus of japonica rice cultivar Zhonghua 11 was infected by Agrobacterium tumefaciens genetic transformation to obtain transgenic plants;finally,compared to Zhonghua 11,two overexpressed and RNA-interfered T₁ transgenic plants with similar phenotypes were selected to measure and analyze the agronomic characteristics such as plant height,panicle length,and leaf angle,changes in root length and coleoptile length at the early stage of germination,and response to brassinolide(BL).The results showed that the plant height of OE-OsBAK1P transgenic rice was dwarfed,the panicle length was shorter,and the leaf angle decreased,meanwhile,the root length increased and the seedling length shortened after seed germination,and the leaves were not sensitive to BL.However,the plant height,panicle length and leaf angle of RNAi-OsBAK1P transgenic rice increased,meanwhile,root length shortened and seedling length increased after seed germination,and the leaves were sensitive to BL.To sum up,these results provide theoretical support for changing rice plant structure to increase grain yield and may provide a reference for further studies on other functions of OsBAK1 and its precursor OsBAK1P.

Key words: Rice, Brassinosteroid, OsBAK1P, Overexpression, RNAi, Phenotype