OsNAC-like transcription factor involved in regulating seed-storage protein content at different stages of grain filling in rice under aerobic conditions.

In this study, we show that NAC-like transcription factor (TF) has 90% sequence similarity with cDNA of the OsNac5 gene present in the NCBI database. Phylogenetic analysis of the NAC gene family was performed with inclusion of the highly diverse C-terminal sequences. We report that this gene is also found to be orthologous to Glycine max NAC8, NAC2, Triticum aestivum NAC6 and paralogous to OsNAC6. mRNA was purified from five recombinant inbred lines (RILs) and parents of rice at three different stages of grain filling under aerobic conditions, with grain protein content (GPC) spanning from 4 to 14%. The NAC-like TF encoding a protein was found to be upregulated at the S2 stage in the leaf (3.9-fold) and panicle (1.84-fold) of parent HPR14 and in five RILs (1.9 to 4.51-fold in leaves and 0.47 to 3.2-fold in panicles). Expression analysis of the NAC-like TF encoding a protein for the rice gene was found to be upregulated at the S2 stage in the leaf and panicle of parental line HPR14 and RILs with high protein content.