Allem A, Tarnai R, Tóth S B, Abido W A E, Dulai S
Department of Botany and Plant Physiology, Faculty of Science, Eszterházy Catholic University, H-3301 Eger, P.O. Box 43, Hungary.
Biological Doctoral School, Hungarian University of Agriculture and Life Sciences, H-2011 Gödöllő, Hungary.
Photosynthetica. 2025 Jul 8;63(2):165-181. doi: 10.32615/ps.2025.019. eCollection 2025.
The thermal stability of photosynthetic apparatus under osmotic/salt stress was examined in wheat cultivars grown under different climatic conditions. The thermostability of nonstressed plants did not differ significantly from each other and it was not improved by osmotic treatment in the absence of light. In contrast, the salt stress resulted in better thermostability. This was also manifested in the temperature dependence of maximal quantum yield of PSII photochemistry. The temperature dependence of steady-state fluorescence and other photosynthetic parameters indicated a moderate reduction in thermal sensitivity of photosynthesis in well-watered plants which was further enhanced by osmotic, but even more by salt treatment. It seems likely that the osmotic stress-induced thermal stability increase of PSII occurs only in energized thylakoids. The temperature dependence of quantum yield of regulated energy dissipation seems to suggest that the secondary effects of lumen pH might have a role in the protective mechanisms concerning these stresses, but salt stress can also affect thermal stability in other ways as well.
在不同气候条件下种植的小麦品种中，研究了渗透/盐胁迫下光合机构的热稳定性。未受胁迫植株的热稳定性彼此间无显著差异，且在无光条件下进行渗透处理也未得到改善。相反，盐胁迫导致了更好的热稳定性。这也体现在PSII光化学最大量子产率的温度依赖性上。稳态荧光和其他光合参数的温度依赖性表明，水分充足的植株光合作用的热敏感性适度降低，渗透处理进一步增强了这种降低，而盐处理的增强作用更大。似乎渗透胁迫诱导的PSII热稳定性增加仅发生在有能量的类囊体中。调节性能量耗散量子产率的温度依赖性似乎表明，腔pH值的次级效应可能在这些胁迫的保护机制中起作用，但盐胁迫也可能以其他方式影响热稳定性。
