CaMAPK9过表达可显著提高拟南芥耐盐水平  

Overexpression of CaMAPK9 Significantly Enhanced Tolerance to Salt Stress in Arabidopsis thaliana

作　　者：林金辉 党峰峰[3] 陈建鸿 薄炳锦 邱爱连 官德义[1,2] 黄荣华[1,2] 何水林[1,2] 

机构地区：[1]福建农林大学作物科学学院,福州350002 [2]福建农林大学教育部作物遗传育种与综合利用重点实验室,福州350002 [3]浙江大学生命科学学院,杭州310000 [4]福建农林大学生命科学学院,福州350002

出　　处：《农业生物技术学报》2017年第10期1612-1621,共10页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(No.31372061;No.31401890;No.31401312和No.31301254)

摘　　要：促分裂素原活化蛋白激酶(mitogen-activated protein kinases,MAPK)级联是广泛参与植物应答逆境的信号传递,但有关MAPK级联在辣椒(Capsicum annuum)中的作用鲜有报道。本研究对辣椒CaMAPK9(登录号:CA04g21490)的应答盐胁迫及外源水杨酸(salicylic acid,SA)、脱落酸(abscisic acid,ABA)处理表达及其在拟南芥中异源表达的表型效应进行了分析。结果表明,CaMAPK9定位于细胞核,其编码基因CaMAPK9的转录受盐胁迫和外源茉莉酸甲酯(methyl Jasmonate,Me JA)和ABA处理的诱导。利用T3代转基因拟南芥纯合株系的种子在盐胁迫下种子萌发率实验结果表明,CaMAPK9的超表达可显著提高拟南芥(Arabidopsis thaliana,Columbia)种子在盐胁迫下的萌发率,CaMAPK9超表达植株在耐盐胁迫下根系长度显著长于对照,并伴随着ABA信号通路的标记基因ABI5(abscisic acid-insensitive5)表达的显著上升。这些结果表明,CaMAPK9可能作为正调控因子参与了ABA和JA信号通路介导的辣椒耐盐胁迫防御反应。本研究为辣椒应答盐胁迫的分子育种机制研究提供理论基础。Despite the greatly agricultural importance of pepper （Capsicum annuum） and the ubiquitously involvement of MAPK （mitogen-activated protein kinases） cascades in a broad range of plant biological processes, the roles of MAPK cascades in pepper remain unclearly. In the present study, a MAPK of pepper, designated as CaMAPK9 （Accession no.： CA04921490）, was expressed and functionally characterized. The results showed that CaMAPK9 shared more than 95% deduced amino acid sequence identity with its homologues in other plant species including tobacco （Nicotiana tabacum）, tomato （Solanum lycopersicum） and potato（Solanum tuberosum）. By subcellular localization assay through transient overexpression of CaMAPK9- GFP （Green Fluorescent Protein） in leaves of Nicotiana benthamiana plants, CaMAPK9 was found to target tothe nuclei. Total RNA was extracted from abiotic stresses imposed pepper plants, as salt, mannitol and foliar application of salicylic acid （SA）, methyl jasmonate （MeJA） or abscisic acid （ABA） and used for first-stand cDNA synthesis, cDNA RT-PCR showed that CaMAPK9 was induced under salt or mannitol and foliar application of SA or ABA stresses but impeded by SA, showing that CaMAPK9 may be involved in salt stress pepper response. In addition, two T3 transgenic Arabidopsis lines were developed and the ectopic overexpression of CaMAPK9 was confirmed. The 2 transgenic lines consistently showed a enhanced tolerance to salt stress manifested by the higher germination rate and longer root length under salt stress compared to that of the wild type seeds of seedlings. The transcriptional expression of ABl5, an ABA maker gene which was responsive to signaling in plant under salt- stress tolerance, was higher in two transgenic Arabidopsis types that in wild plants under salt-stress. All these results collectively suggested that CaMAPK9 acted as a positive regulator in the response of pepper to salt stress possibly regulated by signaling mediated by ABA and JA. This study provides a

关 键 词：辣椒 盐胁迫 MAPK级联 促分裂素原活化蛋白激酶9(Ca MAPK9) 

分 类 号：S184[农业科学—农业基础科学]