紫花苜蓿几丁质酶基因MsChiⅣ克隆及序列分析  

Cloning and Characterization of MsChiⅣ Gene from Medicago sativa L.

作　　者：王步云[1] 李聪[1] 王涌鑫[1] 关宁[1] 苗丽宏[1] 

机构地区：[1]中国农业科学院北京畜牧兽医研究所,牧草遗传育种研究室,北京100193

出　　处：《分子植物育种》2009年第2期347-354,共8页Molecular Plant Breeding

基　　金：国家十一五科技支撑计划(2006BAD01A19);中国农科院院所基金(ywf-td-03)资助

摘　　要：本研究根据截形苜蓿(Medicago truncatula)根部的几丁质酶基因保守序列(GenBank登录号:AF167328)设计引物,通过RT-PCR直接扩增的方法得到了紫花苜蓿(Medicago SativaL.)根部几丁质酶基因保守序列。根据得到的保守序列设计3'端和5'端特异引物,分别从3'端和5'端扩增延长该片段,最后通过序列拼接获得紫花苜蓿根部一种几丁质酶基因的全长cDNA序列,命名为MsChiⅣ(GenBank登录号:FJ487629)。MsChiⅣ基因全长为1025bp,开放性阅读框全长为849bp,编码282个氨基酸,分子量为30.5kD,预测等电点为4.66,其结构包括信号肽、几丁质结合区、糖苷水解酶区,为Ⅳ类几丁质酶,属于几丁质酶第19家族,在氨基酸水平上与截形苜蓿几丁质酶蛋白同源性最高,达到98%。蛋白结构分析表明该基因编码蛋白为非跨膜蛋白,存在于细胞质中。A conserved sequence of the class IV chitinase from the root ofMedicago Sativa L. had been cloned by RT-PCR, with primers designed according to the sequence segment of the class Ⅳ chitinase from Medicago truncatula （GenBank accession number： AF167328）. A cDNA clone encoding the class Ⅳ chitinase from Medicago Sativa L., named as MsChiⅣ （GenBank accession number： FJ487629）, was obtained by rapid-amplification ofcDNA ends （RACE） technology using primers designed in accordance with the conserved sequence of class IV chitinase from Medicago Sativa L.. The 3′ terminal and the 5′ terminal ofMsChiIV gene were cloned by RACE, respectively. The sequence consisted of 1 025 bp and had an open reading frame （ORF） of 849 bp which encoded a protein of 282 amino acids including a signal peptide, chitin-binding domain and glycoside-hydrolase domain. The estimated molecular weight and isoelectric point of the putative protein were 30.5 kD and 4.66, respectively. It showed extensive similarities to the known class IV chitinase of some plants. The similarity was up to 98% in the Medicago truncatula L., In addition, the analysis showed that it was a non-transmembrane protein.

关 键 词：几丁质酶基因 紫花苜蓿 克隆 分析 

分 类 号：S541.9[农业科学—作物学]