紫花苜蓿铝激活半型ABC转运子基因MsSTAR2的耐铝性分析  

MsSTAR2 Encodes a Half-type ATP-binding Cassette Transporter Protein that is Induced by Aluminum in Medicago sativa L.

作　　者：宋文静[1] 王凭青[1] 张宝云[1] 杨青川[2] 蔡冰杰[1] 赖平[1] 康岳华[1] 

机构地区：[1]重庆大学生物工程学院,重庆400030 [2]中国农业科学院北京畜牧兽医研究所/农业部畜禽遗传资源与利用重点开放实验室,北京100193

出　　处：《农业生物技术学报》2013年第5期522-529,共8页Journal of Agricultural Biotechnology

基　　金：国家现代农业产业技术体系建设专项(No.CARS-39);重庆市自然科学基金重点项目(No.CSTC,2009BA1066);中央高校基本科研业务费(No.CDJXS11230004)

摘　　要：酸性土壤中,Al3+和H+根毒性是影响作物生长的主要限制因子。植物已经演化出部分耐受铝毒和质子毒性的机制,而这些生理过程的分子机制仍然很少被描述。本研究在紫花苜蓿(Medicago sativaL.)中克隆出一个编码ABC转运子跨膜域的基因MsSTAR2(GenBank登录号:KC430619),它与水稻(Oryza sativa)耐铝基因OsSTAR2和拟南芥(Arabidopsis thaliana)耐铝基因AtALS3有较高的同源性。MsSTAR2在根、茎和叶组织中都有表达,且在叶中的表达量最高。与OsSTAR2和AtALS3不同,MsSTAR2同时受到Al3+和H+的诱导,但它不响应于其他金属离子,如Cd,Mn等。此外,本研究发现基因的表达量和紫花苜蓿的耐铝性间没有正相关的关系。实验结果表明,MsSTAR2是一个铝激活基因,它可能诱导铝损伤在紫花苜蓿中的保护机制,通过与核酸结合域蛋白相互作用为一个完整的ABC转运子参与苜蓿的抗铝作用中。Severe crop yield losses are caused by the rhizotoxicities of aluminum （Al^3＋） and protons （H＋） in acid soil. Some plant species and cultivars have evolved mechanisms for detoxifying Al^3＋ and H＋, but little is known about molecular mechanisms of their tolerance. Here, we reported a gene, MsSTAR2（GenBank accession no. KC430619）, encoded a transmembrane domain of a bacterial-type ABC transporter in Medicago sativa L., and shared a high similarity with rice（Oryza sativa） OsSTAR2 and Arabidopsis thaliana AtALS3, which had been implicated in aluminum tolerance. MsSTAR2 was constitutively expressed in all tissues and it was predominantly expressed at leaves. Different with OsSTAR2 and AtALS3, either AI^3＋ or H＋ increased the expression of MsSTAR2, but the gene didn＇t respond to other metal ions, such as Cd and Mn. Furthermore, we found that there was no positive correlation between the amount of gene expression and aluminum resistance in Medicago Sativa L. All these results indicated that MsSTAR2 is an aluminum-activated gene in Medicago Sativa L., and it may induce the protection mechanism caused by aluminum damage, which probably functions as a bacterial-type ABC transporter by forming a complex with a nucleotide binding domain protein.

关 键 词：ABC转运子 紫花苜蓿 铝毒 MsSTAR2 

分 类 号：S541.9[农业科学—作物学]