PtrMYB106通过抑制内源脱落酸调节植物高盐胁迫适应能力  

PtrMYB106 Regulates High Salt Stress through the Suppression of Abscisic Acid in Plants

作　　者：汪琼 徐静 彭杰娣 唐晓雯 汪晶 刘驰 涂成杰 尹恒 方庆 Wang Qiong;Xu Jing;Peng Jiedi;Tang Xiaowen;Wang Jing;Liu Chi;Tu Chengjie;Yin Heng;Fang Qing(Key Laboratory of Biological Resources Protection and Utilization of Hubei Province,College of Biological Science and Technology,Hubei Minzu University,Enshi,445000)

机构地区：[1]湖北民族大学生物科学与技术学院生物资源保护与利用湖北省重点实验室

出　　处：《分子植物育种》2019年第23期7901-7908,共8页Molecular Plant Breeding

基　　金：国家自然科学基金(31660186)资助

摘　　要：转录因子(Transcription factor)在植物应激盐分胁迫过程中,发挥重要调节作用。本研究克隆一个杨树MYB-type转录因子,PtrMYB106,以转化拟南芥植株为材料,采用盐胁迫以及现代分子生物学实验技术等方法对其调节盐分胁迫功能进行鉴定。结果显示,转录因子PtrMYB106编码蛋白序列N端包含2个相邻MYB类型的DNA结合结构域(MYB DNA-binding domain),并且每个Domain中各含有一个典型的螺旋-转角-螺旋模体(H-T-H motif),显示其具有调节基因表达的功能。组织和胁迫处理,显示PtrMYB106在根、茎和叶中表达量较高,并且其表达明显受盐分诱导。PtrMYB106过表达的拟南芥植株(35S:PtrMYB106),对高盐胁迫的适应能力较野生型明显降低,表明该转录因子可能负调节盐胁迫。另外,35S:PtrMYB106植株的种子萌发速率要明显快于野生型种子;并且,施用ABA合成抑制剂钨酸钠,并未消除二者之间的差异。进行ELASA实验,结果显示转化35S:PtrMYB106拟南芥植株ABA含量显著下降。qRT-PCR结果显示拟南芥中与盐胁迫和脱落酸密切相关的基因,包括脱落酸合成的关键基因ABA1和种子萌发调节的基因ABI3等,表达量显著下调。以上结果表明,杨树MYB转录因子PtrMYB106借助抑制内源性ABA合成,降低植物对高盐胁迫的适应能力。本研究为深入揭示杨树在高盐胁迫条件下的转录调控机制提供了基础。Transcription factor plays an important role in regulating plant resistance to salt stress.In this study,a poplar MYB-type transcription factor PtrMYB106 was cloned and its function was identified by using the transgenic Arabidopsis plants as material,salt stress and modern molecular biology experiment technology.Results showed that the N-terminal of the PtrMYB106 transcription factor coding protein sequence contained two adjacent MYB DNA-binding domains,and each domain contained a typical helix-turn-helix motif(H-T-H motif),indicating that it had the function of regulating gene expression.Tissue and stress treatments showed that the expression of PtrMYB106 was relatively higher in roots,stems and leaves,and was obviously induced by salt.Arabidopsis thaliana plants(35 S:PtrMYB106)overexpressed by PtrMYB106 showed significantly lower adaptability to high salt stress than that of wild-type plants,indicating that the transcription factor might negatively regulate salt stress.In addition,the seed germination rate of 35 S:PtrMYB106 plants was significantly faster than that of wild type seeds;and the application of sodium tungstate,a synthetic inhibitor of ABA,did not eliminate the difference in germination rate between 35 S:PtrMYB106 plants and wild-type plants.ELASA results showed that the ABA content of transformed 35 S:PtrMYB106 Arabidopsis plants decreased significantly.qRT-PCR results showed that the expression of salt stress and abscisic acid related genes in Arabidopsis thaliana,including ABA1,a key gene for abscisic acid synthesis and ABI3,a gene for seed germination regulation,were clearly down-regulated.The results showed that PtrMYB106 decreased the adaptability of plants to high salt stress by inhibiting endogenous ABA synthesis.This study would provide a basis for future revealing the mechanism of transcriptional regulation in poplar under high salt stress conditions.

关 键 词：MYB转录因子 杨树 盐胁迫 脱落酸 

分 类 号：Q94[生物学—植物学]