1. High Light Acclimation Mechanisms Deficient in a PsbS-Knockout Arabidopsis Mutant
- Author
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Young Nam Yang, Thi Thuy Linh Le, Ji-Hye Hwang, Ismayil S. Zulfugarov, Eun-Ha Kim, Hyun Uk Kim, Jong-Seong Jeon, Dong-Hee Lee, and Choon-Hwan Lee
- Subjects
arabidopsis ,gene expression ,high light acclimation ,plastoquinone synthesis ,PsbS ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The photosystem II PsbS protein of thylakoid membranes is responsible for regulating the energy-dependent, non-photochemical quenching of excess chlorophyll excited states as a short-term mechanism for protection against high light (HL) stress. However, the role of PsbS protein in long-term HL acclimation processes remains poorly understood. Here we investigate the role of PsbS protein during long-term HL acclimation processes in wild-type (WT) and npq4-1 mutants of Arabidopsis which lack the PsbS protein. During long-term HL illumination, photosystem II photochemical efficiency initially dropped, followed by a recovery of electron transport and photochemical quenching (qL) in WT, but not in npq4-1 mutants. In addition, we observed a reduction in light-harvesting antenna size during HL treatment that ceased after HL treatment in WT, but not in npq4-1 mutants. When plants were adapted to HL, more reactive oxygen species (ROS) were accumulated in npq4-1 mutants compared to WT. Gene expression studies indicated that npq4-1 mutants failed to express genes involved in plastoquinone biosynthesis. These results suggest that the PsbS protein regulates recovery processes such as electron transport and qL during long-term HL acclimation by maintaining plastoquinone biosynthetic gene expression and enhancing ROS homeostasis.
- Published
- 2022
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