摘要
气孔由一对保卫细胞组成,且其壁具有不均一加厚的特性(图1),并能敏感地感受内、外环境信号而调节K^+等渗透调节物质进出保卫细胞引起膨压变化,从而控制气孔的大小、调节植物体与外界环境所进行的水分和气体交换。进一步研究发现,以K^+为主的渗透调节物质引起的膨压变化受到许多因子的调控,如ABA可以中介Ca^(2+)作用抑制K^+内向通道或直接作用于K^+外向通道使K^+外流,但ABA影响K^+通道的信号转导途径仍是一个有待进一步探索的课题。大量研究表明,细胞运动与细胞骨架有关。如丝瓜卷须的卷曲运动、胞质环流、花粉管萌发与伸长、含羞草的感震性运动,以及细胞器的运动等都与细胞骨架有关。我们用植物微管特异性解聚剂——甲基胺草磷(APM)以及微丝专一性抑制剂——细胞松驰素B(CB)预处理蚕豆开放或关闭气孔后可明显地抑制Ca^(2+)、ABA、光、K^+等引起的气孔运动,表明微管、微丝可能参与调节气孔的运动过程。
Turgor pressure induced by osmotic substances, such as K+ , Cl- , and malate, stimulates the stomatal movements. Microtubules (MTs) and microfilaments (MFs) may be involved in regulating the stomatal movements. Abscisic acid-induced changes in the orientation of cortical MTs in stomatal movement of Vicia, faba L. were observed with electron microscopy. It was shown that the MTs in the open stomata stimulated by light were oriented in a position transverse to the ventral wall in paradermal sections and parallel to the outer wall in cross sections (MTs were paradermally sectioned). MTs in the closed stomata induced by darkness were parallel to the dorsal and the ventral walls in paradermal sections (MTs were transversely sectioned) and transverse to the outer wall in cross sections (MTs were paradermally sectioned). However, MTs in the closed stomata induced by ABA in the light were oriented both transversely (MTs were paradermally sectioned) and parallel -ly (MTs were paradermally sectioned) to the ventral wall in paradermal sections. The results indicate that the changes of MT orientation induced by ABA are associated with the stomatal movement.
基金
国家自然科学基金
关键词
蚕豆
气孔运动
脱落酸
酸
微管
Vicia faba, Stomata, Abscisic acid, Microtubule
