Abstract: RNA interference (RNAi) technology can be used to specifically suppress the expression of target gene in eukaryotes. In this research, RNAi-inducing vector pCADS1341 was constructed for rice transformtion. In order to examine its effectiveness, RNAi vector targeting GUS gene was constructed using pCADS1341 and introduced into transgenic rice calli stably expressing GUS gene using gene-gun transformation method. GUS staining results indicated that transient expression of the RNAi apparatus could significantly suppress the expression of GUS gene. In order to investigate factors that affect RNAi efficiency, detailed analyses were carried out on rice RNAi plants targeting a given rice receptor-like kinase gene. T-DNA insertion copy number and expression level of target gene in each T0 RNAi plant were detected using Southern blot and Northern blot, respectively. A line with single-copy T-DNA insertion and well-suppressed target gene expression was selected out for semi-quantitative RT-PCR assay on its T1 offspring. The results indicated that RNAi effect could be inherited to the next generation of trangenic rice plants, but the RNAi efficiencies in different individuals were variable. Expression level of RNAi apparatus might determine RNAi efficiency. Our high efficiency RNAi system would play an important role in rice functional genomics research. We have successfully made more than six　RNAi constructs for rice receptor-like kinase genes and systematic functional analysis of those genes are underway.

Key words: RNA interference, T-DNA, Rice