香蕉果实冷胁迫相关MaWRKY11转录因子的特性、互作蛋白筛选与鉴定

为探讨香蕉(Musa acuminata)响应冷胁迫的分子机制,从香蕉果实冷害的数字基因表达谱中筛选并分离了1 个WRKY转录因子,命名为MaWRKY11。MaWRKY11 具有2 个WRKY 保守结构域,属于I 类WRKY 成员,定位于细胞核,是核蛋白。MaWRKY11 具有转录激活活性,且激活区在N 端。实时荧光定量PCR 分析表明MaWRKY11 受冷胁迫诱导,外源茉莉酸甲酯(MeJA)处理减轻香蕉果实冷害的同时也上调了其表达。另外,酵母双杂交筛选表明,MaWRKY11 可与脱水诱导的早期应答蛋白MaERD 相互作用。这些表明MaWRKY11 可能通过与逆境相关蛋白如MaERD 互作来响应香蕉果实的冷胁迫。     

辣椒CaWRKY14转录因子的生物学特性研究

WRKY转录因子是植物响应病原菌胁迫最重要的转录因子之一,且参与抗病反应及信号传导通路的调控。为研究辣椒WRKY基因的生物学特征,以辣椒高抗疫病材料CM334为试材,克隆获得响应疫霉菌诱导的转录因子CaWRKY14。生物信息学分析表明,该基因DNA全长2 530 bp,cDNA全长1 662 bp,含有5个内含子,编码553个氨基酸,含有1个WRKY保守结构域,属于Group Ⅱ(b)。实时荧光定量表达分析表明,CaWRKY14不仅受ABA和疫霉菌胁迫诱导表达,且表达量分别在12 h和24 h时达到峰值,分别是对照的8.54和8.04倍,同时也受高盐、热激和干旱胁迫诱导。利用VIGS技术对CaWRKY14转录因子进行沉默后发现,抗病材料CM334接种疫霉菌后趋于发病。研究表明,CaWRKY14基因在辣椒响应疫霉菌胁迫进程中可能发挥着重要作用。     

香蕉胁迫相关蛋白基因的克隆及其表达分析

通过随机克隆测序的方法从香蕉根系cDNA文库中获得胁迫相关蛋白基因,命名为MaSAP1(GenBank登录号为AGH14257.1)。扩增获得的cDNA序列与质粒OZ092的目的片段序列一致,表明MaSAP1是香蕉SAP基因编码框全长cDNA,包含一个510bp的最大开放阅读框,编码一个长169个氨基酸的蛋白质。蛋白质序列同源比对发现其含有完整的A20和AN1基序结构。系统进化树比对分析表明,MaSAP1与水稻和獐茅的亲缘关系较近。组织特异性研究表明,MaSAP1基因在香蕉根和果实中的表达量较高,在茎中的表达量最低。实时荧光定量PCR分析表明MaSAP1响应激素的处理,同时也响应干旱、低温、高盐和枯萎病菌的侵染等胁迫。可见,MaSAP1基因在植物生长发育和植物响应逆境中具有重要作用。     

Molecular cloning of the cDNA encoding a stress-inducible protein phosphatase 1 (PP1) catalytic subunit from French bean (Phaseolus vulgaris L.)

A cDNA showing high sequence similarity (>70%) to plant protein phosphatase 1 catalytic subunit variants from other species has been isolated from a cDNA library derived from mRNAs expressed in elicitor-treated suspension-cultured cells. The clone appears to be a near full-length 1431 bp with a 172 bp 5-untranslated region and a 317 bp 3-untranslated region. The open reading frame, determined by sequence similarity, codes for a protein with predicted M _r of 35552. Alternatively an ATG situated to the 5 end of the putative start site would increase the protein size by 6 amino acids.The mRNA for Pvpp1 was shown to be rapidly induced by elicitor treatment of suspension-cultured cells of French bean. The cloned cDNA represents one of the few examples of a gene product that is probably involved in dephosphorylation events arising after the initial responses to biotic stress.Abbreviations PAL phenylalanine ammonia-lyase - PP1 protein phosphatase 1 - Pvpp1 Phaseolus vulgaris protein phosphatase 1