由过氧化激活的通道介导护卫细胞中的酸信号传递
1Division of Biology, Cell and Developmental Biology, and Center for Molecular Genetics, University of California at San Diego, La Jolla 92093-0116, USA.
Nature
|August 30, 2000
概括
在干旱期间,植物使用酸 (ABA) 关闭胃口. 过氧化 (H2O2) 激活了警卫细胞中的通道,调解了这一至关重要的干旱反应.
科学领域:
- 植物生理学 植物生理学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 干旱压力对全球农业生产力产生重大影响.
- 酸 (ABA) 是一种关键的植物激素,通过诱导口腔关闭来调节干旱耐受性.
- 护卫细胞中ABA诱导的流和血膜通道激活的精确机制仍然不完全理解.
研究的目的:
- 为了研究过氧化 (H2O2) 在ABA介导的口腔关闭中的作用.
- 在植物保护细胞中识别和描述H2O2激活通道.
- 为了阐明上游信号事件,将ABA感知与流入联系起来.
主要方法:
- 补丁电生理学记录Ca2+电流在阿拉比多普西斯护卫细胞原生质.
- 使用成像测量完整的护卫细胞中的细胞质 ([Ca2+]cyt).
- 对应于ABA和H2O2治疗的口腔孔径的分析.
- 基因分析使用ABA不敏感的突变gca2.
主要成果:
- 过氧化 (H2O2) 直接激活了阿拉比多普西斯护卫细胞的血膜中的Ca2+透通道.
- 这些H2O2激活通道调解Ca2+流入原生体,并在完整的护卫细胞中提升[Ca2+]细胞.
- ABA治疗刺激了护卫细胞中的H2O2产量,阻断这种产量抑制了ABA诱导的口腔关闭.
- 在gca2突变体中,ABA和H2O2诱导的口腔关闭和通道激活受损.
结论:
- 在干旱期间,ABA诱导的口腔关闭涉及防护细胞中H2O2的产生.
- H2O2作为一个关键的信号分子,激活血膜通道.
- 这些H2O2激活通道是植物对干旱耐受性的ABA信号通路的重要组成部分.
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