中文摘要：

根据GenBank上已有的植物cat基因序列,设计一对兼并引物。在海南岛采集香蕉、巴西橡胶、黄灯笼辣椒、菠萝、甘蔗、番木瓜等作物的叶片并提取总RNA,反转录成cDNA,PCR进行同源克隆。结果获得了巴西橡胶cat-1和香蕉的cat-2基因,而未获得其它4种作物cat相关基因。序列分析发现,巴西橡胶cat-1和香蕉的cat-2基因开放阅读框（ORF）都为1 479 bp,编码492个氨基酸,GenBank登陆号分别为HQ660587和HQ660588。生物信息学软件分析巴西橡胶CAT-1和香蕉CAT-2蛋白的三级结构分别与Exiguobacteriu Oxidotolerans（PDB code：2j2mA0）和Pseudomonas Syringae（PDB code：1m7sA）相似。构建系统发育树表明巴西橡胶CAT-1与蓖麻CAT-1氨基酸序列（Ricinus communis：XP_002521709.1）同源性最高,为92.1%;香蕉CAT-2与油棕CAT-2氨基酸序列（Elaeisguineensis：ACF06566.1）同源性最高,达90.9%。

英文摘要：

According to the existence of plant cat genes in GenBank,we designed a pair of degenerate primers,and amplified cat genes of banana,Hevea brasiliensis,yellow lantern pepper,pineapple,sugar cane,papaya from Hainan island.Ultimately,we cloned the rubber cat-1 and banana cat-2 genes,while the others not.Sequence analysis showed that open reading frame（ORF） of rubber cat-1 and banana cat-2 genes were both 1479bp,and encoded 492 amino acids.GenBank accession number were HQ660587 and HQ660588.Using bioinformatics software,the tertiary structures of rubber＇s CAT-1 and banana＇s CAT-2 proteins were predicated,which were similar to Exiguobacteriu Oxidotolerans（PDB code：2j2mA0） and Pseudomonas Syringae（PDB code：1m7sA）,respectively.Phylogenetic analysis indicated that Hainan H.brasiliensis CAT-1 possessed the highest homology with Ricinus communis CAT-1（XP_002521709.1）,while banana CAT-2 was the highest homology with Elaeis guineensis CAT-2（ACF06566.1）.