大麦S-腺苷甲硫氨酸合成酶基因HvSAMS2对非生物胁迫响应的表达分析  

Expression Analysis of S-adenosylmethionine Synthetase Gene HvSAMS2 from Hordeum vulgare in Response to Abiotic Stress

作　　者：张寒冰 张书发 李毛[1] 武军[1] 陈新宏[1] ZHANG Han-Bing;ZHANG Shu-Fa;LI Mao;WU Jun;CHEN Xin-Hong(Shaanxi Key Laboratory of Plant Genetic Engineering Breeding/College of Agronomy,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学农学院/陕西省植物遗传工程育种重点实验,杨凌712100

出　　处：《农业生物技术学报》2021年第1期35-46,共12页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(31571650;31771785);国家重点研发计划(2017YFD0100701);陕西省农业领域重点项目(2018ZDXM-NY-006)。

摘　　要：植物在盐胁迫环境下通过多胺积累提高自身的耐受性,S-腺苷甲硫氨酸合成酶(Sadenosylmethionine synthetase, SAMS)是多胺合成过程中的重要限速酶。本研究从’农家二棱’大麦(Hordeum vulgare)中克隆HvSAMS2基因,分别对其进行生物信息学、组织表达特异性及非生物胁迫响应、亚细胞定位、酿酒酵母(Saccharomyces cerevisiae)中的耐盐性等分析。结果显示,HvSAMS2基因全长为1 297bp,包含长度为1 185 bp的开放阅读框,中间没有内含子;预测蛋白含有394个氨基酸,分子量为42.83 k D,理论等电点为5.58。氨基酸多重比对分析表明,HvSAMS2与不同物种SAMS蛋白之间高度保守,与粗山羊草(Aegilops tauschii) SAMS2具有最高的同源性(一致率为93.06%)。对绿色荧光蛋白的观察显示,HvSAMS2定位于细胞核和细胞膜上,在细胞核分布更多。qRT-PCR检测结果显示,HvSAMS2表达具有组织特异性,大麦根部的HvSAMS2表达量最高,叶部次之,茎中最低;HvSAMS2被干旱、低温、盐及茉莉酸甲酯(methyl jasmonate, MeJA)诱导而显著表达。构建过表达载体pYES2-HvSAMS2,转染酿酒酵母营养缺陷型INVSc1进行异源表达,HvSAMS2基因在盐胁迫下增强了宿主菌的耐盐能力。综上,HvSAMS2可能在响应非生物逆境胁迫过程中具有重要作用,本研究为深入探讨SAMS抗盐的分子机制提供基础资料。Plants increase their tolerance through accumulation of polyamines under salt stress. Sadenosylmethionine synthetase(SAMS) is an important rate-limiting enzyme involved in the biosynthesis polyamines. In this study, HvSAMS2 gene was isolated from farmhouse two-row barley(Hordeum vulgare), and analyzed for bioinformatics, tissue expression specificity and abiotic stress responses, subcellular localization and salt tolerance in Saccharomyces cerevisiae. The full-length c DNA sequence of HvSAMS2 was 1 297 bp without introns, which contained a 1 185 bp ORF that encoded 394 predicted amino acids, with a molecular weight of 42.83 kD and a hypothetical protein isoelectric point of 5.58. Multiple alignment analysis based on the amino acids indicated that HvSAMS2 was highly conserved to SAMS proteins from different species,and had the highest similarity of 93.06% to Aegilops tauschii SAMS2. Subcellular localization revealed that HvSAMS2 was located in the nucleus and cell membrane with a higher level in the nucleus. The qRT-PCR analysis results in different tissues indicated that HvSAMS2 was preferentially accumulated in root, and then leaves, following by stem. Furthermore, HvSAMS2 expression level was significantly enhanced upon drought,low temperature, salt, and methyl jasmonate(MeJA) treatment. Complete gene of HvSAMS2 was inserted into expression vector pYES2 and transformed into Saccharomyces cerevisiae INVSc1 for heterologous expression,and the expressing HvSAMS2 improved the salt tolerance of the engineered strain under salt stress. In summary, HvSAMS2 might play an important role in responding to abiotic stresses, and this study could provide basic data for further study on the molecular mechanism of salt resistance of SAMS genes.

关 键 词：大麦 S-腺苷甲硫氨酸合成酶2基因(SAMS2) 基因克隆 基因表达 逆境耐受性 

分 类 号：S512.3[农业科学—作物学]