Molecular cloning, characterization and expression analysis of three aldehyde oxidase genes from Pisum sativum L.
Molecular cloning, characterization and expression analysis of three aldehyde oxidase genes from Pisum sativum L.
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DOI：
10.1016/j.plaphy.2007.09.011
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
E. Zdunek-Zastocka
中科院分区：
文献类型：
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作者：
E. Zdunek-Zastocka
醛氧化酶（AO, EC 1.2.3.1）是一种被认为催化脱落酸（ABA）和吲哚-3-乙酸（IAA）合成最后一步的钼酸羟化酶。三种编码油菜醛氧化酶蛋白的cdna。采用RT-PCR（逆转录-聚合酶链反应）方法获得小奇迹（Little Marvel）。克隆的基因分别为PsAO1、PsAO2和PsAO3，长度分别为4630、4347和4600bp，与其他植物醛氧化酶具有较高的序列同源性。PsAO1、PsAO2和PsAO3蛋白长度分别为1373、1367和1367个氨基酸，包含两个铁硫中心、一个FAD结合域和一个钼辅因子（Moco）结合域的一致序列。PsAO1和PsAO2主要在成年植株幼苗和幼叶中表达，而PsAO3在衰老叶片和成熟种子中表达量最高。盐度和铵态处理对PsAO2 mRNA无显著影响，但两种胁迫条件下PsAO3转录水平均显著升高，其中老化叶、完全展开叶和根的转录水平变化最为显著。PsAO1转录本水平仅在营养液中存在铵的情况下增强，而在盐度条件下没有增强。基于在控制和胁迫条件下推导出的蛋白的分子质量和器官特异性基因表达，讨论了每个PsAO3 cDNA在形成上述三种二聚体豌豆AO异构体中的贡献，以及PsAO3在脱落酸（ABA）合成中的可能参与。
Aldehyde oxidase (AO, EC 1.2.3.1) is a molybdenohydroxylase that is considered to catalyze the last step of abscisic acid (ABA) and indole-3-acetic acid (IAA) synthesis. Three cDNAs encoding aldehyde oxidase proteins in Pisum sativum (cv. Little Marvel) were obtained based on RT-PCR (reverse transcriptase-polymerase chain reaction) strategy. The cloned genes, designated as PsAO1, PsAO2 and PsAO3, are 4630, 4347, 4600bp in length, respectively, and show high sequence identity to each other and to aldehyde oxidases from other plant species. The deduced PsAO1, PsAO2, and PsAO3 proteins are 1373, 1367, 1367 amino acids in length, respectively, and contain consensus sequences for two iron-sulfur centers, a FAD binding domain, and a molybdenum cofactor (Moco) binding domain. PsAO1 and PsAO2 were mainly expressed in leaves of seedlings and young leaves of adult plants, while the highest PsAO3 transcript level was observed in aging leaves and matured seeds. PsAO2 mRNA was not affected by salinity or ammonium treatment, whereas the transcript level of PsAO3 increased significantly under both stress conditions, with the most pronounced changes in aging leaves, fully expanded leaves and roots. The PsAO1 transcript level was enhanced only in the presence of ammonium in the nutrient medium, but not under salinity. Based on the molecular mass of the deduced proteins and on organ-specific gene expression, studied both under control and stress conditions, the contribution of each PsAO cDNA in the formation of the previously described three dimeric pea AO isoforms and the possible involvement of the PsAO3 in abscisic acid (ABA) synthesis is discussed.