Two Arabidopsis cytochrome P450 monooxygenases, CYP714A1 and CYP714A2, function redundantly in plant development through gibberellin deactivation.
Two Arabidopsis cytochrome P450 monooxygenases, CYP714A1 and CYP714A2, function redundantly in plant development through gibberellin deactivation.
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DOI：
10.1111/j.1365-313x.2011.04596.x
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发表时间：
2011-07
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影响因子：
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通讯作者：
Yingying Zhang;Baicheng Zhang;Dawei Yan;Weixin Dong;Weibing Yang;Qun Li;Longjun Zeng;Jianjun Wang-Jianjun-W
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文献类型：
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作者：
Yingying Zhang;Baicheng Zhang;Dawei Yan;Weixin Dong;Weibing Yang;Qun Li;Longjun Zeng;Jianjun Wang-Jianjun-W
水稻基因 ELONGATED UPPERMOST INTERNODE1 (EUI1) 编码 P450 单加氧酶，可在失活反应中环氧化赤霉素 (GA)。拟南芥基因组包含编码 EUI 同源物的串联重复基因对 ELA1 (CYP714A1) 和 ELA2 (CYP714A2)。在这项工作中，我们剖析了这两种蛋白质的功能。 ELA1 和 ELA2 表现出重叠但不同的基因表达模式。我们发现，虽然 ELA1 或 ELA2 的单一突变体没有表现出明显的形态表型，但同时消除 ELA1-RNAi/ela2 中的 ELA1 和 ELA2 表达会导致生物量增加和器官增大。相比之下，组成型表达 ELA1 或 ELA2 的转基因植物身材矮小，类似于过度表达水稻 EUI 基因的转基因植物。我们还发现，ELA1 的过度表达会导致水稻出现严重的矮化表型，而 ELA2 的过度表达会导致水稻出现有利于育种的半矮化表型。与表型一致，我们发现 ELA1-RNAi/ela2 植物增加了生物活性 GA 的数量，而在 ELA1 和 ELA2 过表达的转基因水稻节间则减少了。相比之下，前体GA(12)在转基因水稻中轻微积累，而GA(19)在ELA2过表达水稻中高度积累。综上所述，我们的研究强烈表明，两种拟南芥 EUI 同源物很可能通过催化类似于水稻 EUI 的生物活性 GA 失活来巧妙地调节植物生长。这两个 P450 也可能在 GA 生物合成途径的早期阶段发挥作用。我们的结果还表明，ELA2 可能成为谷类作物高产潜力分子育种的绝佳工具。
The rice gene ELONGATED UPPERMOST INTERNODE1 (EUI1) encodes a P450 monooxygenase that epoxidizes gibberellins (GAs) in a deactivation reaction. The Arabidopsis genome contains a tandemly duplicated gene pair ELA1 (CYP714A1) and ELA2 (CYP714A2) that encode EUI homologs. In this work, we dissected the functions of the two proteins. ELA1 and ELA2 exhibited overlapping yet distinct gene expression patterns. We showed that while single mutants of ELA1 or ELA2 exhibited no obvious morphological phenotype, simultaneous elimination of ELA1 and ELA2 expression in ELA1-RNAi/ela2 resulted in increased biomass and enlarged organs. By contrast, transgenic plants constitutively expressing either ELA1 or ELA2 were dwarfed, similar to those overexpressing the rice EUI gene. We also discovered that overexpression of ELA1 resulted in a severe dwarf phenotype, while overexpression of ELA2 gave rise to a breeding-favored semi-dwarf phenotype in rice. Consistent with the phenotypes, we found that the ELA1-RNAi/ela2 plants increased amounts of biologically active GAs that were decreased in the internodes of transgenic rice with ELA1 and ELA2 overexpression. In contrast, the precursor GA(12) slightly accumulated in the transgenic rice, and GA(19) highly accumulated in the ELA2 overexpression rice. Taken together, our study strongly suggests that the two Arabidopsis EUI homologs subtly regulate plant growth most likely through catalyzing deactivation of bioactive GAs similar to rice EUI. The two P450s may also function in early stages of the GA biosynthetic pathway. Our results also suggest that ELA2 could be an excellent tool for molecular breeding for high yield potential in cereal crops.