1. CHAPTER One - Singlet oxygen in plants: From genesis to signaling.
- Author
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Mengping Li and Chanhong Kim
- Subjects
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APOPTOSIS , *BIOMOLECULES , *HYDROXYL group , *REACTIVE oxygen species , *NUCLEIC acids , *SUPEROXIDES , *POISONS - Abstract
Singlet oxygen (¹O2) is a non-radical reactive oxygen species (ROS), a photosynthetic byproduct in plants. Like other chloroplastic radicals, such as superoxide and hydroxyl radicals, ¹O2 can damage biological molecules including nucleic acids, lipids, and proteins, exacerbating photoinhibition and oxidative stress. Since the photosystem II reaction center (PSII RC) is a primary place of ¹O2 production, PSII damage, quality control, and reassembly occur as light-driven default processes. In addition, the chloroplast has evolved systems to quench excess light energy and to directly detoxify ¹O2 as counteractive measures. However, upon the first publication of a research article elucidating the genetic basis of ¹O2-triggered stress responses by Klaus Apel's group in 2004, the classical view of ¹O2 as a toxic agent has dramatically changed. Since then, many scientists started the incredible journey of ¹O2-signaling research with more discoveries of ¹O2-overproducing mutants under certain conditions. This chapter summarizes the current knowledge of the biogenesis of photosynthetic and non-photosynthetic ¹O2, PSII damage and repair cycle, and the ¹O2-dependent oxidative modification of biomolecules and related retrograde signaling pathways in plants. In particular, we highlight recent progress in ¹O2 signaling pathways mediated by two spatially separated chloroplast ¹O2 sensors, β-carotene and EXECUTER proteins, as well as possible other branches of the ¹O2 signaling network, providing insights into the importance of ¹O2 in plant stress responses, such as acclimation and programmed cell death. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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