棉花多胺氧化酶基因(GhPAO3)的克隆及表达分析

Cloning and Expression Analysis of Polyamine Oxidase(GhPAO3)Gene in Cotton(Gossypium hirsutum L.)

根据拟南芥AtPAO5的cDNA序列在雷蒙德氏棉数据库中Blastn比对获得同源PAO基因,设计特异性引物并利用RT-PCR技术克隆获得1个陆地棉PAO基因,命名为GhPAO3。对GhPAO3的cDNA序列进行生物信息学分析,结果显示:该基因cDNA全长为1 736bp,开放阅读框为1 530bp,编码506个氨基酸,预测蛋白大小为56.88ku,等电点为5.77,编码蛋白为亲水性蛋白。Real-time PCR结果表明,GhPAO3在不同组织中的表达情况不同,表达量依次是叶>茎>根>花瓣>子房>雄蕊>种子>雌蕊。不同诱导处理下GhPAO3基因表达量也存在差异,其中低温处理和ABA处理后该基因在6h时表达量达到最大值,PEG处理后在24h时表达量达到最大值,NaCl则在处理后3h时表达量最高。表明GhPAO3基因受非生物胁迫诱导表达,可能以不同的角色参与棉花抗逆过程,结果为进一步研究该基因的功能奠定基础。

A homologous polyamine oxidase （PAO） gene was cloned through blastingAtPAO5 cDNA in Raymond＇s cotton genome database. A new PAO was identified using RT-PCR and was named as GhPAO3 in upland cotton. The full length of GhPAO3 cDNA was 1 736 bp,including a 1 530 bp open reading frame,encoding 506 amino acid residues,and the molecular weight of predicted protein was 56.88 ku,isoelectric point was 5.77. Expression pattern of GhPAO3 was analyzed in different tissues and treatments using real-time PCR. The results suggested that the order of expression level of Gh- PAO3 was leaf〉 stem〉 root〉 petal〉 ovary〉 stamen〉 seed〉 pistil. Besides, expression levels of GhPA03 were significantly changed under different treatments. Expression level of GhPAO3 reached the highest level at 6 h under low temperature and ABA treatment, whereas the highest expression level of GhPAO3 occurred at 3 h and 24 h under NaCl and PEG treatments,respectively. These results indicated that GhPAO3 is induced by abiotic stresses, and will play an important role in defending against abiotic stress in cotton.