OsNAC52, a rice NAC transcription factor, potentially responds to ABA and confers drought tolerance in transgenic plants

Abstract

A novel NAC (NAM, ATAF1/2, CUC2) homologous gene, OsNAC52, was isolated from Oryza sativa L using RACE (rapid amplification of cDNA ends). Analysis of the amino acid sequence of OsNAC52 revealed a highly conserved NAC domain and a potential nuclear localization sequence in its N-terminus, and the transcriptional activation motif in the C-terminal region. Transgenic plants over-expressing OsNAC52 were highly sensitive to ABA (Abscisic acid), and the growth of the 35S-OsNAC52 transgenic seedlings was significantly more restrained by ABA treatment than those of the wild-type seedlings. Furthermore, over-expression of OsNAC52 activated the expression of downstream genes in transgenic Arabidopsis, resulting in enhanced tolerance to drought stresses but not growth retardation. The results from this study indicate that this novel rice OsNAC52 gene functions as an important transcriptional activator in ABA-inducible gene expression and may be useful in improving plant tolerance to abiotic stress.