Abstract
We found more than 50 predicted NAC proteins in rice. These proteins were classified into 11 subgroups Groups A to K by sequence similarity. Microarray analysis revealed that five genes including OsNAC6 among six genes in the Group A were induced by dehydration, high-salinity, and low temperature. Northern and promoter:GUS analysis showed that the expression of the OsNAC6 gene was also induced by abscisic acid, jasmonic acid, and wounding. The transactivation assay using a yeast system revealed that the OsNAC6 protein function as a transcriptional activator. The transient assay showed that the OsNAC6-sGFP fusion protein is localized in the nucleus. Transgenic Arabidopsis and rice plants overexpressing OsNAC6 showed dwarf phenotype. The results of microarray analysis revealed that many abiotic- and biotic-stress-inducible genes were up-regulated in the OsNAC6-overexpressed Arabidopsis and rice plants. These results indicate that OsNAC6 functions as a transcriptional activator under biotic and abiotic stresses in plants.
