Bei Zhanlin, Zhang Xin, Tian Xingjun
School of Life Sciences, Nanjing University, Nanjing 210023, China.
School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China.
Biology (Basel). 2023 Jul 20;12(7):1024. doi: 10.3390/biology12071024.
Leaves are essential for plants, enabling photosynthesis and transpiration. In arid regions, water availability limits plant growth. Some plants, like , a sandy sub-tree species widely distributed in arid and semi-arid regions, have unique leaf structures to reduce water loss and solar radiation. Here, we describe the leaves of L., with special functioning trichomes. Through leaf submicroscopic structure observation, in situ water collection experiments, photosynthesis measurements, and reflection spectrum analysis, we investigated leaves, focusing on their functioning trichomes. These trichomes capture water vapor, reflect UV and NIR light, and possess a 3D interface structure composed of 1D and 2D structures. The 1D conical structure captures water droplets, which are then gathered by the radial conical structure and guided towards the stomata through wedge-shaped grooves on the 2D umbrella structure. The trichomes also reflect sunlight, with micropapillae reflecting UV light and the umbrella structure reflecting NIR light. These mechanisms reduce leaf temperature, respiration, and water transpiration, protecting against solar radiation damage. This study provides insights into water collection and light-reflection mechanisms, revealing adaptive strategies of plants with large leaves in arid regions.
叶子对植物至关重要，能实现光合作用和蒸腾作用。在干旱地区，水分供应限制了植物生长。一些植物，如广泛分布于干旱和半干旱地区的沙地亚树种 ，具有独特的叶片结构以减少水分流失和太阳辐射。在此，我们描述了具有特殊功能毛状体的 叶片。通过叶片亚微观结构观察、原位集水实验、光合作用测量和反射光谱分析，我们对 叶片进行了研究，重点关注其功能毛状体。这些毛状体捕获水蒸气，反射紫外线和近红外光，并拥有由一维和二维结构组成的三维界面结构。一维锥形结构捕获水滴，然后由径向锥形结构聚集，并通过二维伞状结构上的楔形凹槽导向气孔。毛状体还反射阳光，微乳头反射紫外线，伞状结构反射近红外光。这些机制降低了叶片温度、呼吸作用和水分蒸腾，防止太阳辐射损伤。本研究为集水和光反射机制提供了见解，揭示了干旱地区大叶植物的适应性策略。
