Key Laboratory of Biodiversity and Environment on the Qinghai-Tibetan Plateau, Ministry of Education, School of Ecology and Environment, Tibet University, Lhasa, 850000, China.
Aquatic Plant Research Center, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
Photosynth Res. 2024 Oct;162(1):47-62. doi: 10.1007/s11120-024-01115-4. Epub 2024 Aug 12.
Aquatic plants are a crucial component of the aquatic ecosystem in the Tibetan Plateau region. Researching the adaptability of plateau aquatic plants in photosynthesis to the plateau environment can enhance understanding of the operational mechanisms of plateau ecosystems, thereby providing a scientific basis for the protection and management of plateau aquatic ecosystems. This study presents an investigation of photosynthetic inorganic carbon utilization strategies and photosynthetic efficiency of 17 aquatic plants under natural growing conditions in Niyang River basin on the Tibetan Plateau. In pH-drift experiments, 10 of 17 species were able to utilize HCO, and environmental factors like water pH were shown to have a significant effect on the ability of the tested species to utilize HCO. Titratable acidity in the leaves of Stuckenia filiformis, Zannichellia palustris, Batrachium bungei, and Myriophyllum spicatum showed significant diurnal fluctuations at certain sampling sites, indicating the presence of CAM. In B. bungei, water pH positively correlated with CAM activity, while CO concentration negatively correlated with CAM activity. The chlorophyll fluorescence analysis revealed that aquatic plants inhabiting the Tibetan Plateau exhibited photosynthetic adaptations. In conclusion, the aquatic plants on the Tibetan Plateau employ diverse strategies for utilizing inorganic carbon during photosynthesis, exhibiting their flexible adaptability to the native high-altitude habitats of the Tibetan Plateau.
青藏高原地区的水生植物是水生生态系统的重要组成部分。研究高原水生植物在光合作用中对高原环境的适应性，可以增强对高原生态系统运行机制的理解，从而为高原水生生态系统的保护和管理提供科学依据。本研究对青藏高原尼洋河流域自然生长条件下的 17 种水生植物的光合作用无机碳利用策略和光合效率进行了调查。在 pH 漂移实验中，17 种中有 10 种能够利用 HCO，环境因素如水的 pH 值对测试物种利用 HCO 的能力有显著影响。在某些采样点，穗状狐尾藻、菹草、溪荪和竹叶眼子菜叶片中的可滴定酸度表现出明显的昼夜波动，表明存在 CAM。在溪荪中，水的 pH 值与 CAM 活性呈正相关，而 CO 浓度与 CAM 活性呈负相关。叶绿素荧光分析表明，青藏高原上的水生植物表现出光合作用的适应性。总之，青藏高原上的水生植物在光合作用中采用多种策略来利用无机碳，表现出对青藏高原本土高海拔生境的灵活适应性。
