F-Box Protein DOR Functions As a Novel Inhibitory Factor for Abscisic Acid-Induced Stomatal Closure under Drought Stress in Arabidopsis1[C][W]
F-Box Protein DOR Functions As a Novel Inhibitory Factor for Abscisic Acid-Induced Stomatal Closure under Drought Stress in Arabidopsis1[C][W]
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DOI：
10.1104/pp.108.126912
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发表时间：
2008-10
期刊：
影响因子：
7.4
通讯作者：
Yu’e Zhang;Wenying Xu;Zhonghui Li;X. Deng;Weihua Wu;Yongbiao Xue
中科院分区：
文献类型：
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作者：
Yu’e Zhang;Wenying Xu;Zhonghui Li;X. Deng;Weihua Wu;Yongbiao Xue
在叶表皮中形成气孔的保卫细胞感知并整合环境信号以调节气孔孔径以响应不同的条件。在干旱胁迫下，植物会合成脱落酸（ABA），进而诱导气孔快速关闭，以防止蒸腾作用造成的水分流失。然而，ABA 介导的气孔关闭的分子机制的许多方面仍不清楚。在这里，我们报道了拟南芥（Arabidopsis thaliana）中保卫细胞 ABA 信号传导的新型负调节因子 DOR。 DOR 基因编码一种假定的 F-box 蛋白，它是与 AhSLF-S2 相关的 S 位点 F-box 样家族的成员，并与 ASK14 和 CUL1 特异性相互作用。 DOR 的无效突变导致气孔关闭的超敏感 ABA 反应，并显着提高耐旱性；相反，过表达DOR的转基因植物更容易受到干旱胁迫的影响。 DOR 在保卫细胞中强烈表达并被 ABA 处理抑制，表明 DOR 在 ABA 反应中存在负反馈循环。 dor 与 ABA 不敏感突变体 abi1-1 的双突变分析表明，abi1-1 与 dor 上位，但在野生型和 dor 之间未检测到磷脂酶 Dα1 的明显变化。 Affymetrix GeneChip 分析表明，DOR 可能在干旱胁迫下调节 ABA 生物合成。综上所述，我们的结果表明，DOR 在 ABA 信号通路中独立于磷脂酶 Dα1 发挥作用，抑制干旱胁迫下 ABA 诱导的气孔关闭。
Guard cells, which form stoma in leaf epidermis, sense and integrate environmental signals to modulate stomatal aperture in response to diverse conditions. Under drought stress, plants synthesize abscisic acid (ABA), which in turn induces a rapid closing of stoma, to prevent water loss by transpiration. However, many aspects of the molecular mechanism for ABA-mediated stomatal closure are still not understood. Here, we report a novel negative regulator of guard cell ABA signaling, DOR, in Arabidopsis (Arabidopsis thaliana). The DOR gene encodes a putative F-box protein, a member of the S-locus F-box-like family related to AhSLF-S2 and specifically interacting with ASK14 and CUL1. A null mutation in DOR resulted in a hypersensitive ABA response of stomatal closing and a substantial increase of drought tolerance; in contrast, the transgenic plants overexpressing DOR were more susceptible to the drought stress. DOR is strongly expressed in guard cells and suppressed by ABA treatment, suggesting a negative feedback loop of DOR in ABA responses. Double-mutant analyses of dor with ABA-insensitive mutant abi1-1 showed that abi1-1 is epistatic to dor, but no apparent change of phospholipase Dα1 was detected between the wild type and dor. Affymetrix GeneChip analysis showed that DOR likely regulates ABA biosynthesis under drought stress. Taken together, our results demonstrate that DOR acts independent of phospholipase Dα1 in an ABA signaling pathway to inhibit the ABA-induced stomatal closure under drought stress.