拟南芥保卫细胞中G蛋白对离子通道及脱落酸信号的调控

G protein regulation of ion channels and abscisic acid signaling in Arabidopsis guard cells.

作者信息

Wang X Q, Ullah H, Jones A M, Assmann S M

机构信息

Biology Department, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802-5301, USA.

出版信息

Science. 2001 Jun 15;292(5524):2070-2. doi: 10.1126/science.1059046.

DOI:10.1126/science.1059046

PMID:11408655

Abstract

The phytohormone abscisic acid (ABA) promotes plant water conservation by decreasing the apertures of stomatal pores in the epidermis through which water loss occurs. We found that Arabidopsis thaliana plants harboring transferred DNA insertional mutations in the sole prototypical heterotrimeric GTP-binding (G) protein alpha subunit gene, GPA1, lack both ABA inhibition of guard cell inward K(+) channels and pH-independent ABA activation of anion channels. Stomatal opening in gpa1 plants is insensitive to inhibition by ABA, and the rate of water loss from gpa1 mutants is greater than that from wild-type plants. Manipulation of G protein status in guard cells may provide a mechanism for controlling plant water balance.

摘要

植物激素脱落酸（ABA）通过减小表皮气孔孔径来促进植物保水，水分正是通过这些气孔流失的。我们发现，在唯一的典型异源三聚体GTP结合（G）蛋白α亚基基因GPA1中存在转移DNA插入突变的拟南芥植株，既缺乏ABA对保卫细胞内向K(+)通道的抑制作用，也缺乏pH非依赖性的ABA对阴离子通道的激活作用。gpa1植株的气孔开放对ABA的抑制不敏感，gpa1突变体的水分流失速率高于野生型植株。调控保卫细胞中的G蛋白状态可能为控制植物水分平衡提供一种机制。