Abstract
The OsNAC5 gene is a member of the stress-responsive NAC transcription factor gene family in rice. There are many homologous genes to OsNAC5 or OsNAC6 in monocot crops, respectively. We analyzed function of the OsNAC5 gene homologous to OsNAC6. Expression of OsNAC5 was induced by high salinity, and the OsNAC5 protein was localized in nucleus. Transactivation experiments using a rice protoplast system showed that OsNAC5 had a transcriptional activation domain in the C-terminal region. We generated the transgenic rice plants overexpressing OsNAC5, and found that transgenic plants showed enhanced tolerance against high-salinity. Microarray analysis of the transgenic rice plants overexpressing OsNAC5 revealed that many stress-responsive genes including LEA proteins were up-regulated. Transactivation experiments showed that OsNAC5 enhanced the expression of the LEA promoter. These data indicate that OsNAC5 is one of important transcription factors controlling the expression of many stress-responsive genes including LEA proteins.
