银杏叶绿体铜锌超氧化物歧化酶基因GbCuZnSOD的克隆与表达  

Isolation and Expression of the Chloroplast Copper /Zinc Superoxide Dismutase Gene (GbCuZnSOD) from Ginkgo biloba

作　　者：李琳玲[1,2] 程华[2] 许锋[3] 王燕[3] 姜德志[3] 程水源[2] 

机构地区：[1]河北农业大学园艺学院,保定071001 [2]黄冈师范学院生命科学与工程学院,黄冈438000 [3]长江大学园艺园林学院,荆州434025

出　　处：《林业科学》2010年第6期35-42,共8页Scientia Silvae Sinicae

基　　金：教育部新世纪优秀人才支持计划(NCET-04-0746);湖北省教育厅重大科技项目(Z200627002);湖北省青年杰出人才基金(2003AB014)

摘　　要：利用RACE技术首次从银杏中克隆得到铜锌型超氧化物歧化酶基因(GbCuZnSOD)的cDNA序列。GbCuZnSOD的cDNA全长为783bp。基因内部含有1个长度为642bp开放阅读框,编码长度为213个氨基酸残基的蛋白质,预测分子质量为21.95ku,等电点为6.82。三维结构预测结果显示,GbCuZnSOD含有3个转角环和8个β折叠构成桶状的活性中心。GbCuZnSOD氨基酸序列与其他植物的CuZnSOD具有很高的相似性。进化树分析结果表明GbCuZnSOD和其他物种的CuZnSOD源自于相同的祖先。信息学分析显示,得到的GbCuZnSOD属于叶绿体SOD。Southern杂交证实,GbCuZnSOD属于一个小的多基因家族。Northern杂交表明GbCuZnSOD在银杏的茎、叶和果中有表达,根中没有表达,在叶中的表达量最高。ABA和36℃高温能诱导GbCuZnSOD的转录表达,而低温和渗透压处理结果不明显。A full-length cDNA sequence of Ginkgo biloba chloroplast copper /zinc-superoxide dismutase gene （GbCuZnSOD,FJ555020） was isolated from G. biloba for the first time. The full-length cDNA of GbCuZnSOD was 783 bp,including a 642 bp open reading frame （ORF） which was deduced to encode a 213-amino-acid protein. A predicted molecular weight of the protein was 21. 8 ku with pI of 6. 82. Three-dimension structure modeling showed that GbCuZnSOD contained 3 helixes and 8 sheets,and had a cylinder motif and three external loops in the enzyme core. Phylogenetic tree analysis revealed that GbCuZnSOD shared the same ancestor with other CuZnSODs. Bioinformatic analysis showed that the CuZnSOD contained a chloroplast-targeted transit peptides. Southern analysis showed that the GbCuZnSOD genes was encoded by a small gene family in G. biloba. Northern hybridization analysis showed that GbCuZnSOD expressed in leaves,stems and fruits,with the highest expression in leaves. There was no expression found in roots. The expression of GbCuZnSOD could be induced by ABA and 36 ℃ temperature,but not by osmoticums and low temperature.

关 键 词：银杏 CuZnSOD基因 表达分析 

分 类 号：S718.46[农业科学—林学] Q943.2[生物学—植物学]