Specific and heritable genetic interference by double-stranded RNA in Arabidopsis thaliana

We investigated the potential of double-stranded RNA interference (RNAi) wi th gene activity in Arabidopsis thaliana. To construct transformation vecto rs that produce RNAs capable of duplex formation, gene-specific sequences i n the sense and antisense orientations were linked and placed under the con trol of a strong viral promoter. When introduced into the genome of A. thal iana by Agrobacterium-mediated transformation. double-stranded RNA-expressi ng constructs corresponding to four genes, AGAMOUS (AG), CLAVATA3. APETALA1 . and PERIANTHIA, caused specific and heritable genetic interference. The s everity of phenotypes varied between transgenic lines. In situ hybridizatio n revealed a correlation between a declining AG mRNA accumulation and incre asingly severe phenotypes in AG (RNAi) mutants, suggesting that endogenous mRNA is the target of double-stranded RNA-mediated genetic interference. Th e ability to generate stably heritable RNAi and the resultant specific phen otypes allows us to selectively reduce gene function in A. thaliana.