棉花多胺氧化酶基因(GhPAO_2)的克隆及非生物胁迫下的表达分析

Cloning and Expression Analysis of GhPAO_2 Gene in Cotton(Gossypium hirsutum L.)

本研究以拟南芥多氨氧化酶(AtPAO2)为探针,在雷蒙德氏棉基因组数据库中获得同源基因并设计引物,利用RT-PCR技术克隆PAO基因,分离一个新的陆地棉PAO基因命名为GhPAO2。该基因cDNA全长为2 237 bp,具有一个1473 bp的开放阅读框,编码490个氨基酸残基,预测该基因蛋白质分子量为54.41 kD,等电点为5.69。利用Real-time PCR对该基因在不同组织和多种非生物胁迫处理进行表达分析,结果表明:GhPAO2基因主要在棉花花瓣和叶中表达;不同胁迫处理下GhPAO2基因表达量均发生显著变化,其中低温处理和20%PEG处理后基因表达量迅速上升并在1 h时表达量达到最高,200 mmol/L NaCl和1 mmol/L ABA处理则在24 h时表达量达到最高,表明GhPAO2基因受低温、PEG、Na Cl和ABA诱导表达,可能在棉花抵御非生物胁迫过程中发挥重要作用。

A homologous polyamine oxidase(PAO) gene was obtained through blasting At PAO2 cDNA in Raymond's cotton genome database.A new PAO was isolated using RT-PCR and named as GhPAO2 in upland cotton.The full length of GhPAO2 cDNA was 2 237 bp,including a 1 473 bp open reading frame,encoding 490 amino acid residues,and the predicted protein molecular weight was 54.41 kD,isoelectric point was 5.69.Expression pattern of GhPAO2 was analyzed in different tissues and treatments using real-time PCR.The results suggested that GhPAO2 had a relatively high expression level in leaves and flower petals.Expression levels of GhPAO2 were significantly changed in different treatments.Expression of GhPAO2 was quickly increased and reached the highest level at 1 h under low temperature and 20% PEG treatment,whereas the highest expression level of GhPAO2 was at 24 h under200 mmol/L NaCl and 1 mmol/L ABA treatments.These results indicated that expression of GhPAO2 induced by abiotic stresses might play an important role in defending against abiotic stress in cotton.