Plastoquinone in and beyond photosynthesis

Michel Havaux (1)

1 PEPSS - Plant Environmental Physiology and Stress Signaling

Plastoquinone-9 (PQ-9) is an essential component of photosynthesis that carries electrons in the linear and alternative electron transport chains, and is also a redox sensor that regulates state transitions and gene expression. However, a large fraction of the PQ pool is located outside the thylakoid membranes, in the plastoglobules and the chloroplast envelopes, reflecting a wider range of functions beyond electron transport. This review describes new functions of PQ in photoprotection, as a potent antioxidant, and in chloroplast metabolism as a cofactor in the biosynthesis of chloroplast metabolites. It also focuses on the essential need for tight environmental control of PQ biosynthesis and for active exchange of this compound between the thylakoid membranes and the plastoglobules. Through its multiple functions, PQ connects photosynthesiswith metabolism, light acclimation, and stress tolerance

Domaines: Sciences du Vivant [q-bio]

Michel Havaux. Plastoquinone in and beyond photosynthesis. Trends in Plant Science, 2020, 25, pp.1252 - 1265. ⟨10.1016/j.tplants.2020.06.011⟩. ⟨hal-03493691⟩