棉花类LRR抗病蛋白(GhLRR-RL)基因的克隆及表达分析  

Cloning and Characterization of a LRR Resistance Like ( GhLRR-RL) Protein Gene from Cotton ( Gossypium hirsutum L.)

作　　者：肖月华[1] 罗明[1] 侯磊[1] 罗克明[1] 罗小英[1] 裴炎[1] 

机构地区：[1]西南农业大学生物技术中心,重庆400716

出　　处：《Acta Genetica Sinica》2002年第7期653-658,T001-T002,共8页

基　　金：国家自然科学基金 (3 983 0 2 40 );教育部博士点基金资助 (1999 0 0 60 0 3)~~

摘　　要：从棉花胚珠的cDNA AFLP片段中 ,选取一个与拟南芥类LRR抗病蛋白 (LRR RL)序列相似的片段 ,用RACE方法延伸其 3′和 5′未知序列 ,得到一个棉花类LRR抗病蛋白的全长cDNA序列 (GenBank登录号 :AY0 4 0 5 32 )。该cDNA长 12 5 9bp ,包含一个 987bp的开放阅读框 ,具有Poly(A)加尾信号。推测的蛋白质包含 32 8个氨基酸 ,其中大部分是LRR区 ,其序列符合膜外LRR的共有序列LXXLXXLXXLXLXXNXGXIPXX。序列和结构比较分析表明 :该棉花LRR RL蛋白与拟南芥的两个类LRR抗病蛋白高度同源 ,而与植物的其他LRR蛋白结构不同 ,推测LRR RL蛋白属于一类新的LRR蛋白。斑点杂交和 3′RACE扩增表明 ,棉花LRR RL基因具有组成性表达的特点。LRR (Leucine rich repeat) proteins are involved in various biological processes. RACE was used to extend the 5′ and 3′ unknown sequence of a cDNA AFLP fragment from cotton ovule, which had sequence similarity to the Arabidopsis thaliana LRR resistance like (LRR RL) protein. By joining the sequence of cDNA AFLP fragment and its 3′ and 5′ RACE product, it was found that the full length cDNA (GenBank Accession No. AY040532) of 1259bp contained an ORF of 987 bp and a putative poly(A) signal. The deduced polypeptide contained 328 amino acids, and consisted of 10 LRRs with extracytoplasmic LRR consensus LXXLXXLXXLXLXXNXGXIPXX. It was demonstrated that the LRR RL proteins of cotton and A. thaliana were highly homologous, with a distinct structure from other plant LRR proteins, suggesting that LRR RL proteins belonged to a new LRR protein family. Using 3′ RACE, the expression of LRR RL gene was detected in root, hypocotyls, fiber, and ovules in various developmental stages.

关 键 词：棉花 LRR蛋白 LRR-RL蛋白 3′RACE 5′RACE 

分 类 号：Q943.2[生物学—植物学]