Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
Int J Mol Sci. 2022 Mar 29;23(7):3768. doi: 10.3390/ijms23073768.
Functions of the photosynthetic apparatus of C3 ( L.) and C4 ( L.) plants under physiological conditions and after treatment with different NaCl concentrations (0-200 mM) were investigated using chlorophyll a fluorescence (pulse-amplitude-modulated (PAM) and JIP test) and P photooxidation measurement. Data revealed lower density of the photosynthetic structures (RC/CSo), larger relative size of the plastoquinone (PQ) pool (N) and higher electron transport capacity and photosynthetic rate (parameter R) in C4 than in C3 plants. Furthermore, the differences were observed between the two studied species in the parameters characterizing the possibility of reduction in the photosystem (PSI) end acceptors (REo/RC, REo/CSo and δRo). Data revealed that NaCl treatment caused a decrease in the density of the photosynthetic structures and relative size of the PQ pool as well as decrease in the electron transport to the PSI end electron acceptors and the probability of their reduction as well as an increase in the thermal dissipation. The effects were stronger in pea than in maize. The enhanced energy losses after high salt treatment in maize were mainly from the increase in the regulated energy losses (Φ), while in pea from the increase in non-regulated energy losses (Φ). The reduction in the electron transport from Q to the PSI end electron acceptors influenced PSI activity. Analysis of the P photooxidation and its decay kinetics revealed an influence of two PSI populations in pea after treatment with 150 mM and 200 mM NaCl, while in maize the negligible changes were registered only at 200 mM NaCl. The experimental results clearly show less salt tolerance of pea than maize.
采用叶绿素荧光（脉冲调制（PAM）和 JIP 测试）和 P 光氧化测量技术，研究了 C3（L.）和 C4（L.）植物光合作用器官在生理条件下和不同 NaCl 浓度（0-200mM）处理后的功能。结果表明，C4 植物的光合作用结构（RC/CSo）密度较低，质体醌（PQ）池（N）相对较大，电子传递能力和光合速率（参数 R）较高。此外，在这两种研究物种中，还观察到了表征光系统（PSI）末端受体还原可能性的参数（REo/RC、REo/CSo 和 δRo）存在差异。结果表明，NaCl 处理导致光合作用结构密度和 PQ 池相对大小降低，PSI 末端电子受体的电子传递减少，其还原的概率增加，热耗散增加。在豌豆中，这种影响比玉米更强。高盐处理后玉米中增强的能量损失主要来自于调节能量损失（Φ）的增加，而在豌豆中则来自于非调节能量损失（Φ）的增加。电子从 Q 到 PSI 末端电子受体的传递减少影响 PSI 活性。P 光氧化及其衰减动力学分析表明，150mM 和 200mM NaCl 处理后豌豆中有两个 PSI 群体的影响，而在玉米中仅在 200mM NaCl 处理后才记录到可忽略的变化。实验结果清楚地表明，豌豆的耐盐性低于玉米。
