School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia.
J Integr Plant Biol. 2017 Apr;59(4):240-260. doi: 10.1111/jipb.12523. Epub 2017 Mar 16.
The evolution of active stomatal closure in response to leaf water deficit, mediated by the hormone abscisic acid (ABA), has been the subject of recent debate. Two different models for the timing of the evolution of this response recur in the literature. A single-step model for stomatal control suggests that stomata evolved active, ABA-mediated control of stomatal aperture, when these structures first appeared, prior to the divergence of bryophyte and vascular plant lineages. In contrast, a gradualistic model for stomatal control proposes that the most basal vascular plant stomata responded passively to changes in leaf water status. This model suggests that active ABA-driven mechanisms for stomatal responses to water status instead evolved after the divergence of seed plants, culminating in the complex, ABA-mediated responses observed in modern angiosperms. Here we review the findings that form the basis for these two models, including recent work that provides critical molecular insights into resolving this intriguing debate, and find strong evidence to support a gradualistic model for stomatal evolution.
主动关闭气孔以响应叶片水分亏缺的进化，由激素脱落酸（ABA）介导，这是最近争论的主题。文献中反复出现了两种不同的关于这种反应进化时间的模型。一种关于气孔控制的单步模型表明，当这些结构首次出现，在苔藓植物和维管植物谱系分化之前，气孔就进化出了主动的、由 ABA 介导的气孔开度控制。相比之下，一种关于气孔控制的渐变模型提出，最基础的维管植物气孔对叶片水分状况的变化被动响应。这个模型表明，主动的 ABA 驱动机制来响应水分状况的气孔反应是在种子植物分化之后进化而来的，最终导致了在现代被子植物中观察到的复杂的 ABA 介导的反应。在这里，我们回顾了形成这两个模型基础的发现，包括最近的工作，这些工作为解决这一有趣的争论提供了关键的分子见解，并找到了强有力的证据支持气孔进化的渐变模型。
