RNAi Vectors for Manipulation of Gene Expression in Higher Plants

摘要

RNA interference (RNAi) is a homology-dependent gene silencing technology in which small interferingRNAs (siRNAs) direct RNA cleavage or DNA methylation. After transcription of an RNAi cassette including inverted repeatsequences against the target gene and a spacer fragment, the resultant transcript forms a hairpin-like structure. Thestem region of hairpin RNAs is processed into siRNAs. Here we focus on the structural properties of RNAi vectors thataffect the silencing efficiency, and caveats in the evaluation of RNAi phenotype are discussed. Subsequently, severalRNAi applications including simultaneous silencing of multiple gene sequences and specific silencing of a member in thegene family were discussed. In addition a newly developed RNAi technology, artificial microRNA, is also introduced.