Shi Qi, Wang Xiao-Qian, Zeng Zhi-Lan, Huang Wei
Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Antioxidants (Basel). 2022 Nov 24;11(12):2325. doi: 10.3390/antiox11122325.
Fluctuating light (FL) can cause the selective photoinhibition of photosystem I (PSI) in angiosperms. In nature, leaves usually experience FL conditions with the same low light and different high light intensities, but the effects of different FL conditions on PSI redox state and PSI photoinhibition are not well known. In this study, we found that PSI was highly reduced within the first 10 s after transition from 59 to 1809 μmol photons m s in tomato (). However, such transient PSI over-reduction was not observed by transitioning from 59 to 501 or 923 μmol photons m s. Consequently, FL (59-1809) induced a significantly stronger PSI photoinhibition than FL (59-501) and FL (59-923). Compared with the proton gradient (∆pH) level after transition to high light for 60 s, tomato leaves almost formed a sufficient ∆pH after light transition for 10 s in FL (59-501) but did not in FL (59-923) or FL (59-1809). The difference in ∆pH between 10 s and 60 s was tightly correlated to the extent of PSI over-reduction and PSI photoinhibition induced by FL. Furthermore, the difference in PSI photoinhibition between (59-923) and FL (59-1809) was accompanied by the same level of linear electron flow. Therefore, PSI photoinhibition induced by different intensities of FL is more related to the kinetics of ∆pH formation rather than linear electron flow.
波动光（FL）可导致被子植物中光系统I（PSI）的选择性光抑制。在自然环境中，叶片通常会经历相同低光强和不同高光强的波动光条件，但不同波动光条件对PSI氧化还原状态和PSI光抑制的影响尚不清楚。在本研究中，我们发现，番茄从59 μmol光子·m⁻²·s⁻¹转变为1809 μmol光子·m⁻²·s⁻¹后的最初10秒内，PSI高度还原。然而，从59 μmol光子·m⁻²·s⁻¹转变为501 μmol光子·m⁻²·s⁻¹或923 μmol光子·m⁻²·s⁻¹时，未观察到这种短暂的PSI过度还原。因此，FL（59 - 1809）诱导的PSI光抑制比FL（59 - 501）和FL（59 - 923）显著更强。与高光处理60秒后的质子梯度（∆pH）水平相比，番茄叶片在FL（59 - 501）中光转变10秒后几乎形成了足够的∆pH，但在FL（59 - 923）或FL（59 - 1809）中则没有。10秒和60秒时∆pH的差异与FL诱导的PSI过度还原程度和PSI光抑制紧密相关。此外，（59 - 923）和FL（59 - 1809）之间PSI光抑制的差异伴随着相同水平的线性电子流。因此，不同强度的FL诱导的PSI光抑制更多地与∆pH形成的动力学有关，而不是线性电子流。
Zotero 插件
