State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, People's Republic of China.
Plant Cell Rep. 2011 Jan;30(1):27-36. doi: 10.1007/s00299-010-0937-2. Epub 2010 Oct 26.
Guard cell walls of stomata are highly specialized in plants. Previous research focused on the structure and anatomy of guard cell walls, but little is known about guard cell regulation during stomata movement. In this work, we investigate the possible biological role of the Arabidopsis expansin gene AtEXPA1 in stomatal opening. The AtEXPA1 promoter drove the expression of the GUS reporter gene specifically in guard cells. Light-induced stomatal opening was accelerated in 35S::AtEXPA1 lines, whereas the anti-AtEXPA1 antibody decelerated light-induced stomatal opening. The inhibition of the anti-AtEXPA1 antibody on stomatal opening was largely dependent on the environmental pH. The volumetric elastic modulus (ε) was measured as an indicator of changes in the cell wall. The ε value of guard cells in 35S::AtEXPA1 lines was smaller than in the wild types. The putative role of AtEXPA1 as controller of stomatal opening rate and its regulation are discussed.
保卫细胞的细胞壁在植物中高度特化。以前的研究主要集中在保卫细胞细胞壁的结构和解剖上，但对保卫细胞在气孔运动过程中的调节知之甚少。在这项工作中，我们研究了拟南芥扩展蛋白基因 AtEXPA1 在气孔开放中的可能生物学作用。AtEXPA1 启动子驱动 GUS 报告基因在保卫细胞中特异性表达。35S::AtEXPA1 系中光诱导的气孔开度加快，而抗 AtEXPA1 抗体则减缓光诱导的气孔开度。抗 AtEXPA1 抗体对气孔开度的抑制在很大程度上取决于环境 pH 值。体积弹性模量（ε）作为细胞壁变化的指标进行测量。35S::AtEXPA1 系中保卫细胞的 ε 值小于野生型。讨论了 AtEXPA1 作为气孔开度控制器的作用及其调节。
