van den Berg Tomas E, Sanders Remco G P, Kaiser Elias, Schmitz Jurriaan
Integrated Devices and Systems, University of Twente, Enschede, the Netherlands.
Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, Wageningen, the Netherlands.
Plant Cell Environ. 2025 Jun;48(6):4533-4549. doi: 10.1111/pce.15436. Epub 2025 Mar 2.
Stomata regulate plant gas exchange under changing environments, but observations of single stomata dynamics in planta are sparse. We developed a compact microscope system that can measure the kinetics of tens of stomata in planta simultaneously, with sub-minute time resolution. Darkfield imaging with green light was used to create 3D stacks from which 2D surface projections were constructed to resolve stomatal apertures. Stomatal dynamics of Chrysanthemum morifolium (Chrysanthemum) and Zea mays (Maize) under changing light intensity were categorized, and a kinetic model was fitted to the data for quantitative comparison. Maize stomata transitioned frequently between open and closed states under constant growth light and these 'opening and closing' stomata, when closed, responded faster to a change to saturating light than steady-state closed stomata under the constant growth light. The faster opening response benefits CO uptake under saturating light. The slow closure of Chrysanthemum stomata reduced water use efficiency (WUE). Over 50% showed delayed or partial closure, leading to unnecessarily large apertures after reduced light. Stomata with larger apertures had more lag and similar closure speeds compared to those with smaller apertures and lag, further reducing WUE. In contrast, maize stomata with larger apertures closed faster, with no lag.
气孔在不断变化的环境中调节植物的气体交换，但对植物中单个气孔动态的观察却很少。我们开发了一种紧凑型显微镜系统，它能够以亚分钟级的时间分辨率同时测量植物中数十个气孔的动力学。利用绿光进行暗场成像以创建三维堆栈，并从中构建二维表面投影以解析气孔孔径。对菊花和玉米在光照强度变化下的气孔动态进行了分类，并对数据拟合了动力学模型以进行定量比较。在恒定生长光照下，玉米气孔在开放和关闭状态之间频繁转换，这些“开合”气孔在关闭时，对饱和光变化的响应比恒定生长光照下的稳态关闭气孔更快。更快的开放响应有利于在饱和光下吸收二氧化碳。菊花气孔关闭缓慢降低了水分利用效率（WUE）。超过50%的气孔表现出延迟或部分关闭，导致光照减弱后孔径不必要地变大。与孔径较小且有滞后现象的气孔相比，孔径较大的气孔滞后更明显且关闭速度相似，进一步降低了水分利用效率。相比之下，孔径较大的玉米气孔关闭更快，没有滞后现象。
