Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs Platz 2, Würzburg, D-97082, Germany.
School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, 7001, TAS, Australia.
New Phytol. 2024 Dec;244(6):2295-2310. doi: 10.1111/nph.20172. Epub 2024 Oct 6.
The evolution of adjustable stomatal pores, enabling CO acquisition, was one of the most significant events in the development of life on land. Here, we investigate how the guard cell signalling pathways that regulate stomatal movements evolved. We compare fern and angiosperm guard cell transcriptomes and physiological responses, and examine the functionality of ion channels from diverse plant species. We find that, despite conserved expression in guard cells, fern anion channels from the SLAC/SLAH family are not activated by the same abscisic acid (ABA) pathways that provoke stomatal closure in angiosperms. Accordingly, we find an insensitivity of fern stomata to ABA. Moreover, our analysis points to a complex evolutionary history, featuring multiple gains and/or losses of SLAC activation mechanisms, as these channels were recruited to a role in stomatal closure. Our results show that the guard cells of flowering and nonflowering plants share similar core features, with lineage-specific and ecological niche-related adaptations, likely underlying differences in behaviour.
可调气孔的进化使植物能够获取 CO，这是陆地生命发展过程中的重要事件之一。在这里，我们研究了调节气孔运动的保卫细胞信号通路是如何进化的。我们比较了蕨类植物和被子植物保卫细胞的转录组和生理反应，并研究了来自不同植物物种的离子通道的功能。我们发现，尽管蕨类植物阴离子通道 SLAC/SLAH 家族在保卫细胞中具有保守表达，但它们并不像被子植物那样被同一套引发气孔关闭的脱落酸 (ABA) 途径所激活。因此，我们发现蕨类植物的气孔对 ABA 不敏感。此外，我们的分析表明，这些通道被招募到参与气孔关闭的过程中，这一机制具有复杂的进化历史，包括 SLAC 激活机制的多次获得和/或丧失。我们的研究结果表明，开花植物和非开花植物的保卫细胞具有相似的核心特征，同时也具有谱系特异性和生态位相关的适应性，这可能是行为差异的基础。
