矮牵牛PhUGT74E2基因的克隆及对逆境胁迫的响应  

Cloning of Glycosyltransferase PhUGT74E2 Gene from Petunia and Its Response to Stress

作　　者：董丽丽[1] 王雪娣 刘同瑞 高迪 王琦 熊枫 LIN Rongyan;FANG Nengyan;LUO Yuanhua;HUANG Minling;YE Xiuxian;ZHONG Huaiqin(Crops Research Institute,Flower Research Center,Fujian Academy of Agricultural Sciences,Fujian Engineering Research Center for Characteristic Floriculture,Fuzhou 350013,China)

机构地区：[1]安徽农业大学园艺学院

出　　处：《西北植物学报》2019年第10期1725-1730,共6页Acta Botanica Boreali-Occidentalia Sinica

基　　金：安徽省自然科学研究面上项目(1808085MC85);国家自然科学基金(31902042)

摘　　要：糖基化转移酶(UGTs)能够维持植物体内的激素平衡,广泛参与植物的生长发育及逆境胁迫应答。该研究从矮牵牛(Petunia hybrida var. Mitchel diploid)中克隆了UGT74E2的同源基因PhUGT74E2及其启动子序列,并分析了序列特征和蛋白结构特点,同时采用qRT-PCR对该基因在不同组织、不同逆境胁迫下的转录水平进行了检测,以探讨矮牵牛UGT74E2基因的功能,为揭示其调控矮牵牛抗逆性的分子机制奠定基础。结果显示:(1)成功克隆获得矮牵牛UGT74E2基因全长序列,命名为PhUGT74E2。(2)PhUGT74E2基因cDNA全长1 986 bp,包含一个1 347 bp开放阅读框,编码448个氨基酸;其蛋白分子式为C2278H3544N586O676S18,分子量为50.53 kDa,等电点为5.18;PhUGT74E2无信号肽和跨膜域,主要定位于叶绿体;同时克隆了PhUGT74E2基因上游2 083 bp启动子序列,该序列中含有脱落酸、赤霉素、光及逆境等响应元件。(3)系统进化树分析显示,PhUGT74E2与其他物种UGT74E2起源相同,而与烟草NtUGT74E2的亲缘关系最近。(4)荧光定量PCR分析表明,PhUGT74E2基因在叶片、茎、根、叶腋和顶端5个组织中均有表达,其中叶腋中的表达量最高,而茎和根中的表达量最低;PEG6000模拟干旱处理及NaCl处理均引起了PhUGT74E2表达水平的显著上调,且随着时间的延长表达水平相应增加,说明PhUGT74E2能够参与矮牵牛对干旱及盐胁迫的响应。Glycosyltransferase can maintain the hormone balance in plants and widely participate in plant growth and development and stress response. PhUGT74E2, the homologous gene of UGT74E2 and its promoter sequence were cloned from petunia(Petunia hybrida var. Mitchel diploid). The sequence characteristics and protein structure characteristics were analyzed,to study the function of petunia UGT74E2, and laid a theoretical foundation for further research on the function of PhUGT74E2 and its molecular mechanism regulating the stress tolerance of petunia. The results showed:(1) the homologous gene of UGT74E2 was cloned from petunia(Petunia hybrida var. Mitchel diploid), named PhUGT74E2.(2) The full length of PhUGT74E2 was 1 986 bp, encoding 448 amino acids. The molecular formula of the protein was speculated to be C2278H3544N586O676S18. The molecular weight was 50.53 kD and the isoelectric point was 5.18. No signal peptide and transmembrane domain were found in PhUGT74 E2, and the protein was mainly located in chloroplast. The promoter sequence of 2 083 bp upstream of PhUGT74E2 gene was also cloned. The sequence contains abscisic acid, gibberellin, light and stress response elements.(3) Phylogenetic tree analysis showed that PhUGT74 E2 had the same origin as other species, but was most closely related to tobacco NtUGT74 E2.(4) Fluorescence quantitative PCR analysis showed that PhUGT74E2 gene was expressed in leaves, stems, roots, axil and apical. The expression level of PhUGT74E2 in axil was the highest, while the lowest in stems and roots. Both PEG6000 and NaCl treatments caused significant upregulation of PhUGT74E2 expression, and the expression level increased with time. The result indicated that PhUGT74E2 was involved in drought and salt stress response of petunia.

关 键 词：矮牵牛 UGT74E2 启动子 干旱胁迫 盐胁迫 表达分析 

分 类 号：Q785[生物学—分子生物学] Q786