Cloning And Functional Analysis Of Rice Genes Related To Fertility

The development of the anther and pollen is an important aspect in the plant genomic research. The defection of anther and pollen development may result in male sterility. Male-sterile is the basis to produce hybrid seeds in agriculture. Thus, the research of anther and pollen development has importance for both basic research and agricultural application.At present, over twenty anther specific genes related to fertility have been cloned in arabidopsis. In rice, however, only a few genes essential for pollen development has been identified. In this paper, we investigated the function of rice genes homologous to Arabidopsis male sterile genes in the anther development using reverse genetics strategy. At first, a total of eight rice candidate genes were chosen via Blast search of Arabidopsis genes in rice genome. After the vectors for expressing dsRNA of these genes were constructed, they were transformed into O.sativa japonica by Agrobacterium-mediated transformation. Transgenic plants were obtained for all of these constructs.The rice P0491E01 gene shares high similarity in amino acid sequence with Arabidopsis genes AtDAD1 (DEFECTIVE IN ANTHER DEHISCENCE1) which plays a key role in the biosynthesis of jasmonic acid. And it was found to be orthologous with AT4G16820 gene. At first, dsRNA expressing vector pP0491RNAi with 263bp-longed exon fragment of P0491E01 was constructed .Ten transgenic plants were obtained after Agrobacterium-mediated transformatioa GUS-staining and PCR analysis confirmed that T-DNA had integrated into rice genome. Three of the transgenic plants were male sterile, and the other transgenic plants showed reduced fertility. Cytological observation indicated that anther development in the early stage of male sterile transgenic plants was normal, however, the microspores could not develop into mature pollen grains. Further investigations of the expression of P0491E01 gene in these transgenic lines by RT-PCR revealed that its transcript was significantly reduced. Our results suggest that P0491E01 may play an important role during the late stage of anther development.