Molecular cloning, subcellular localization analysis, and expression characterization of ZjNAC2 from Zoysia japonica

NAC is one of the largest transcription factor families unique to plants, and plays an important role in regulating plant growth and development and responding to abiotic stress. In this study, the ZjNAC2 gene was cloned from Zoysia japonica using the RACE method. Its coding region is 1 110 bp in length, encoding 369 amino acids. Conserved domain analysis showed that the ZjNAC2 has a typical NAM domain at the N-terminus, indicating that ZjNAC2 belongs to the NAC transcription family. At the same time, the 1 574 bp promoter sequence was obtained using a genome walking method. Cis-elements prediction demonstrated that there were many different response elements within the promoter, such as ABA and abiotic stress-responsive cis-elements. Subcellular localization results showed that ZjNAC2 was located in the nucleus. Real-time quantitative PCR analysis showed that ZjNAC2 was expressed most abundantly in roots and was significantly enriched in senescent leaves. In addition, ZjNAC2 expression was inhibited by 200 μmol·L^–1 ET, 10 μmol·L^–1 MeJA, 10 μmol·L^–1 ABA, or 20% PEG4000, but induced by 300 mmol·L^–1 NaCl treatment. This study demonstrates that ZjNAC2 is an important transcription factor which could be involved in multiple signaling pathways. The present study paves the way to further study the functions of ZjNAC2 in Zoysia japonica.