NAC (NAM, ATF1/2 and CUC2) is a transcription factor that can regulate many physiological and biochemical reactions in plants. Two NAC genes, SNAC4 (NM_001279348.2) and SNAC9 (NM_001365397.1), with similar secondary structures have been isolated from tomato (Solanum lycopersicum L.). The pattern of SNAC4/9 co-regulation of tomato ripening with abscisic acid (ABA) and ethylene through yeast two-hybrid and bimolecular fluorescence complementation assays has revealed that SNAC4/9 can interact with genes related to ABA and ethylene (SAPK3, SlPYL9, SlAREB1, SlACS2 and SlACO1) at the protein level. Electrophoretic mobility shift assay and yeast one-hybrid showed that SNAC4, but not SNAC9, acts directly on the promoter regions of SAPK3, SlCYP707A1, SlACS8 and SlACO6 and can activates them. In addition, quantitative real-time PCR analyses of SNAC4/9-silenced fruit obtained by virus-induced gene silencing, and phytohormone-treated fruit, confirmed that the interaction genes are regulated by SNAC4/9 and thereby affect fruit ripening. In summary, we found that SNAC4/9 can regulate fruit ripening by positively acting on key genes in the synthesis and signal transduction of ABA and ethylene. SNAC4/9 cooperates with these phytohormones as part of the tomato fruit ripening regulatory network.

NAC（NAM，ATF1 / 2和CUC2）是一种转录因子，可以调节植物中的许多生理和生化反应。两个NAC基因，SNAC4（NM_001279348.2）和SNAC9（NM_001365397.1），具有类似的二级结构已经从番茄中分离（番茄L.）。SNAC4 / 9通过酵母双杂交和双分子荧光互补分析共同调控脱落酸（ABA）和乙烯成熟的番茄的模式表明，SNAC4 / 9可以与ABA和乙烯相关的基因相互作用（SAPK3，SlPYL9， SlAREB1，SlACS2和SlACO1）的蛋白质水平。电泳迁移率迁移分析和酵母一杂交表明，SNAC4，而不是SNAC9，直接作用于SAPK3，SlCYP707A1，SlACS8和S1ACO6的启动子区域，并可以激活它们。另外，通过病毒诱导的基因沉默获得的SNAC4 / 9沉默的果实和植物激素处理的果实的定量实时PCR分析证实，相互作用基因受SNAC4 / 9调控，从而影响果实的成熟。总之，我们发现SNAC4 / 9可通过积极作用于ABA和乙烯的合成和信号转导中的关键基因来调节果实成熟。SNAC4 / 9 与这些植物激素合作，作为番茄果实成熟调控网络的一部分。