Identification and expression pattern of one stress-responsive NAC gene from Solanum lycopersicum

NAC (for NAM, ATAF1, 2, and CUC2) family genes have been found to play an important role in diversified developmental processes and environmental responses. A new NAC-type transcription factor SlNAC3 was primarily identified and isolated from the cDNA libraries of tomato cultivar Ailsa Craig. It contains three exons and two introns within genomic DNA sequence and encodes a polypeptide of 329 amino acids. A plant-specific and conserved NAC domain is located in the N-terminus of SlNAC3. The protein SlNAC3 is subcellularly localized in the nucleus of onion epidemical cells and it has a transcriptional activation domain in the C-terminal region which shows extremely divergent among NACs. Phylogenetic analysis showed that SlNAC3 belonged to the OsNAC3 subgroup of the NAC protein family. Tissue expression profile analysis revealed that SlNAC3 was expressed mainly in flower, fruit and root. The transcription expression of SlNAC3 was inhibited by salt, drought stress and ABA treatment. These data demonstrate that SlNAC3 might interact with environmental and endogenous stimuli and probably function when plants response to salt and drought stresses through ABA signaling pathways as a transcriptional activator.