Comprehensive expression analysis of Arabidopsis GA2-oxidase genes and their functional insights
Comprehensive expression analysis of Arabidopsis GA2-oxidase genes and their functional insights
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拟南芥 GA2-氧化酶基因的综合表达分析及其功能见解
DOI：
10.1016/j.plantsci.2019.04.023
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发表时间：
2019-08-01
期刊：
影响因子：
5.2
通讯作者：
Zhang, Yonghong
中科院分区：
文献类型：
--
作者：
Li, Chen;Zheng, Lanlan;Zhang, Yonghong
具有生物活性的赤霉素（GAs）在植物生长发育和逆境响应中起着多种作用。GA 2-氧化酶（GA 2 oxs）是一类2-酮戊二酸依赖性双加氧酶，其调节生物活性GA的失活。在这项研究中，我们研究了拟南芥基因组中存在的7个GA 2 ox基因的遗传和结构域结构。利用转译报告基因系统对7个GA 2 ox基因的表达进行了分析，结果表明：GA 2 ox 1在下胚轴和侧根原基中特异表达，GA 2 ox 2在地上部组织中高表达，GA 2 ox 3在早期胚囊和花序合点胚乳中表达，GA 2 ox 3在胚囊和花序合点胚乳中表达，GA 2 ox 3在胚囊和花序合点胚乳中表达，GA 2 ox 4在胚囊和花序合点胚乳中表达，GA 2 ox 4在胚囊和花序合点胚乳中表达。GA 2 ox 4在茎顶端分生组织和侧根发生过程中表达; GA 2 ox 6在成熟区表达，但不在根的分生组织或伸长区表达; GA 2 ox 7在几乎所有发育阶段组成型表达; GA 2 ox 8仅在气孔细胞中表达。每个这些GA 2 ox基因的过表达抑制高温诱导的下胚轴伸长在野生型和伸长的下胚轴5植物，具有延长的下胚轴表型，这表明这些基因负调节下胚轴伸长通过降低生物活性GA水平。本研究为进一步阐明GA 2 ox基因在不同发育阶段的作用提供了宝贵的资源。
Bioactive gibberellins (GAs) play multiple roles in plant development and stress responses. GA2-oxidases (GA2oxs) are a class of 2-oxoglutarate-dependent dioxygenases that regulate the deactivation of bioactive GAs. In this study, we investigated the phylogeny and domain structures of the seven GA2ox genes present in the Arabidopsis thaliana genome. Comprehensive expression analysis using translational reporter lines showed that the seven GA2ox genes are differentially expressed during Arabidopsis growth and development: GA2ox1 is specifically expressed in the hypocotyl and lateral root primordium; GA2ox2 is highly expressed in aboveground tissues; GA2ox3 is expressed in the chalazal endosperm of the early embryo sac and inflorescences; GA2ox4 is expressed in the shoot apical meristem and during lateral root initiation; GA2ox6 is expressed in the maturation zone, but not in the meristem or elongating zone of the root; GA2ox7 is constitutively expressed during almost all developmental stages; and GA2ox8 is exclusively expressed in stomatal cells. Overexpression of each of these GA2ox genes inhibited high temperature-induced hypocotyl elongation in both wild-type and elongated hypocotyl 5 plants, which have an elongated hypocotyl phenotype, suggesting that these genes negatively regulate hypocotyl elongation by reducing bioactive GA levels. This study provides a valuable resource for further elucidating the roles of GA2ox genes during different stages of development.