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.
出处
《林业科学》
EI
CAS
CSCD
北大核心
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)
关键词
银杏
CuZnSOD基因
表达分析
Ginkgo biloba
copper /zinc-superoxide dismutase gene （CuZnSOD）
expression analysis
