柑橘CsNAC2在果实绿霉病抗病性中的功能和机制研究  

Studies on Function and Mechanism of CsNAC2 Transcription Factor in Resistance to Green Mold in Citrus

作　　者：陈琪 李婷 陈佳琳 陈鸥 王文军[1,2] 姚世响 曾凯芳[1,2,3] CHEN Qi;LI Ting;CHEN Jialin;CHEN Ou;WANG Wenjun;YAO Shixiang;ZENG Kaifang(College of Food Science,Southwest University,Chongqing 400715,China;Research Center of Food Storage&Logistics,Southwest University,Chongqing 400715,China;National Citrus Engineering Technology Research Center,Chongqing 400712,China)

机构地区：[1]西南大学食品科学学院,重庆400715 [2]西南大学食品贮藏与物流研究中心,重庆400715 [3]国家柑桔工程技术研究中心,重庆400712

出　　处：《园艺学报》2023年第12期2701-2712,共12页Acta Horticulturae Sinica

基　　金：国家自然科学基金面上项目(31972126);重庆市科技局重庆市技术创新与应用发展专项重点项目(cstc2021jscx-cylhX0015)。

摘　　要：为探究柑橘转录因子CsNAC2对果实绿霉病抗病性的影响,以‘锦橙447’为材料,克隆了CsNAC2的编码序列。通过生物信息分析、酵母单杂交、RNA-Seq、凝胶迁移实验和qRT-PCR,探究柑橘转录因子CsNAC2对果实绿霉病抗性的调控作用。结果表明,CsNAC2编码区序列为909bp,编码302个氨基酸,其蛋白质分子量为34.40 kD。CsNAC2具备NAC家族转录因子的结构特点,在N端含有保守的NAC结构域。在柑橘果实上瞬时过表达CsNAC2能够有效降低果实绿霉病的发病率和病斑直径。转录组分析发现CsNAC2能够参与果实中多个与抗病相关的代谢途径,对木质素合成途径以及氨基酸和核苷酸糖代谢途径进行深入研究发现,CsNAC2能够分别结合这两个途径中的CsLAC7和CsEP3的启动子,瞬时过表达CsNAC2能够提高CsLAC7和CsEP3的表达量。上述结果表明,CsNAC2可能通过激活CsLAC7和CsEP3的表达,从而提高柑橘果实对绿霉病的抗性。In order to investigate the effect of citrus transcription factor CsNAC2 on resistance to green mold,the coding sequence of CsNAC2 was cloned using‘Jincheng 447'as study material.Bioinformatics analysis,yeast one-hybrid assay,RNA-Seq,EMSA and qRT-PCR were employed to explore the regulatory function of CsNAC2 on fruit green mold resistance.The results showed that the coding sequence of CsNAC2 is 909 bp,encoding 302 amino acids,and the molecular weight of the protein is 34.40 kD.CsNAC2 possesses the structural characteristics of the NAC family and contains conserved NAC domain in the N terminal.Transient overexpression of CsNAC2 on citrus fruit could effectively reduce the incidence of green mold in fruit,with a considerable decrease in incidence and spot diameter.Transcriptomic analysis showed that CsNAC2 can participate in several metabolic pathways related to disease resistance in fruits.Further studies on lignin synthesis pathway,amino acid and nucleotide sugar metabolism pathway showed that CsNAC2 can bind the CsLAC7 and CsEP3 gene promoters in these two pathways,respectively.Transient overexpression of CsNAC2 increased the expression of CsLAC7 and CsEP3 genes.The comprehensive results indicated that CsNAC2 may activates the expression of CsLAC7 and CsEP3 genes to enhance the resistance to green mold in citrus fruits.

关 键 词：柑橘 绿霉病 转录因子CsNAC2 抗病性 分子机制 

分 类 号：S666[农业科学—果树学]