一个水分胁迫应答蛋白与小麦抗旱性的关系及其基因的定位  

Relationship between a Water Stress Responsive Protein and Drought Resistance and Molecular Mapping of the Target Gene in Common Wheat

作　　者：金秀锋[1] 王宪国[1] 任万杰[1] 张晓科[1] 谢惠民[1] 范锋贵[1] 

机构地区：[1]西北农林科技大学农学院/国家小麦改良中心杨凌分中心,陕西杨凌712100

出　　处：《作物学报》2014年第2期198-204,共7页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(30971770);引进国际先进农业科学技术计划(948计划)项目(2011G-3);西北农林科技大学唐仲英育种基金项目资助

摘　　要：分析与小麦抗旱性密切相关的水分胁迫应答蛋白,定位蛋白基因并挖掘与其连锁的分子标记对小麦抗旱分子辅助选择具有重要意义。在一年两点田间全生育期抗旱性鉴定基础上,以-0.5 MPa PEG-6000模拟干旱胁迫处理小麦幼苗48 h,并应用SDS-PAGE方法检测分子量约66.2 kD的水分胁迫应答蛋白,分析其表达与小麦抗旱性的关系。在128个小麦品种(系)中,检测出67份表达该蛋白,另61份未表达该蛋白;前者的平均抗旱指数为1.00,而后者为0.80,有极显著差异(P<0.01),且各抗旱性等级中表达该蛋白的品种比例随着抗性等级的降低而减小。利用晋麦47×西农2208杂交后代230个F3株系进行遗传分析,发现该蛋白表达由1对显性基因控制;目的基因与位于小麦5AS染色体上的5个SSR标记(Xgwm129、Xgwm304、Xbarc56、Xbarc117和Xbarc197)连锁,位于邻近标记Xbarc56和Xbarc117之间,遗传距离分别为2.2 cM和2.9 cM。用这2个紧密连锁标记检测128个小麦品种(系),有67个品种(系)与晋麦47具有相同的标记位点,其中86.6%的品种(系)(58/67)在水分胁迫后表达目标蛋白。该约66.2 kD的水分胁迫应答蛋白与小麦的抗旱性密切相关,与其紧密连锁的分子标记可为小麦抗旱分子辅助选择提供依据。Proteins in response to water stress may closely relate to drought resistance in plants. Genes encoding such proteins are potentially used in wheat breeding aiming to improve drought resistance. The drought resistance of 128 wheat varieties （lines） was identified in two locations in the 2010-2011 growing season. These varieties were then subjected to SDS-PAGE analysis for a -66.2 kD water stress responsive protein after seedling treatment with -0.5 MPa PEG-6000 for 48 h. Sixty-seven varieties showed expression of the target protein, whereas the remaining 61 varieties absented from the protein expression. Drought resistance in- dex （DI） revealed significant difference between the two groups of varieties （1.00 for protein-positive varieties and 0.80 for pro- tein-negative varieties, P 〈 0.01）, and the ratio of protein-positive varieties in each DI level decreased with the decrease of DI value. A dominate gene was found to encode the -66.2 kD protein using the F3 population derived from Jinmai 47 × Xinong 2208, which was composed of 230 lines. The target gene was located on chromosome 5AS of wheat, linking to SSR markers Xgwm129, Xgwm304, Xbarc56, Xbarc117, and Xbarc197. The closest flanking markers were Xbarc56 and Xbarcll 7 with genetic distances of 2.2 cM and 2.9 cM, respectively. To validate the effectiveness of SSR markers, we conducted PCR amplification in the 128 varie- ties using Xbarc56 and Xbarc117 primers. Sixty-seven varieties amplified the same band as that in Jinmai 47 （high drought resis- tance）, in which 86.6% （58/67） expressed the -66.2 kD protein after PEG-6000 treatment. Apparently, this -66.2 kD water stress responsive protein has a close relationship with drought resistance in common wheat, and the SSRs flanking to its coding gene are useful in marker-assisted selection.

关 键 词：小麦 水分胁迫应答蛋白 抗旱指数 基因标记定位 

分 类 号：S512.1[农业科学—作物学]