Arvaniti Elena, Levizou Efi, Kyparissis Aris
Department of Biological Applications and Technology, University of Ioannina, 451 10 Ioannina, Greece.
Department of Agricultural Crop Production and Rural Environment, University of Thessaly, Fytokou Str., 384 46 Volos, Greece.
Plants (Basel). 2023 Jun 29;12(13):2484. doi: 10.3390/plants12132484.
In the present study, the diaheliotropic leaf movement pattern of in relation to the impact of low temperature is presented. Seasonal measurements of movement characteristics along with important aspects of plant function, such as chlorophyll content, water potential, PSII photochemistry, and phenological parameters were performed on plants in their natural environment. During the study period, low winter temperatures and a 10-day freezing event gave insights into the plant's response to harsh environmental conditions and the effect of the latter on leaf movement profile. Plant growth was significantly inhibited during low-temperature periods (leaf shedding) and the photosynthetic performance was seriously depressed, as judged by in vivo chlorophyll fluorescence. Additionally, the diaheliotropic leaf movement pattern was arrested. Temperature rise in March triggered new leaf burst and expansion, enhancement of the photosynthetic performance, and the recovery of the diaheliotropic movement. The daily and seasonal profiles of the water potential were synergistically shaped by leaf movement and climatic conditions. We conclude that diaheliotropism of is a dynamic process that coordinates with the prevailing temperatures in ecosystems like the studied one, reaching a full arrest under near-zero temperatures to protect the photosynthetic apparatus from over-excitation and prevent photoinhibition.
在本研究中，展示了[植物名称]的向日性叶片运动模式与低温影响的关系。在自然环境中对植物进行了运动特征的季节性测量以及植物功能的重要方面，如叶绿素含量、水势、PSII光化学和物候参数的测量。在研究期间，冬季低温和持续10天的冰冻事件使我们深入了解了植物对恶劣环境条件的响应以及后者对叶片运动特征的影响。在低温时期（落叶）植物生长受到显著抑制，通过活体叶绿素荧光判断，光合性能严重下降。此外，向日性叶片运动模式停止。3月气温上升引发了新叶的萌发和扩展、光合性能的增强以及向日性运动的恢复。水势的日变化和季节变化由叶片运动和气候条件共同作用形成。我们得出结论，[植物名称]的向日性是一个动态过程，与像本研究这样的生态系统中的主导温度相协调，在接近零的温度下完全停止，以保护光合机构免受过度激发并防止光抑制。
