The functional characterization of DRB-family dsRNA-binding proteins in Arabidopsis thaliana by using transgenic plants over-expressing DRB genes

Abstract

HYL1/DRB family, which has two double-strand RNA(dsRNA) binding motifs in its N-terminal region, is one of the dsRNA binding protein families in Arabidopsis thaliana. In animal, the homologous genes are associated with RNA silencing/RNAi machinery. Similarly, in A. thaliana, HYL1/DRB1 and DRB4 were reported to be associated with RNA silencing/RNAi. However, the involvement of RNA silencing or the functions of DRB2, DRB3 and DRB5 are not yet to be characterized. Therefore, we performed the functional analysis with transgenic plants over-expressing these DRB genes. These plants showed the leaf morphological abnormality and the change of small RNA accumulation. These results indicate that DRB2, DRB3 and DRB5 are associated with RNA silencing machinery as well as DRB1 and DRB4 are. We are further studying to understand the association between DRBs and RNA silencing and functional diversity of DRB-family proteins.