Tanned or sunburned: How excessive light triggers plant cell death

Stefano d'Alessandro (1, 2) , Inès Beaugelin (2) , Michel Havaux (2)

1 LGBP - Luminy Génétique et Biophysique des Plantes
2 PEPSS - Plant Environmental Physiology and Stress Signaling

Plants often encounter light intensities exceeding the capacity of photosynthesis (excessive light) mainly due to biotic and abiotic factors, which lower CO$_2$ fixation and reduce light energy sinks. Under excessive light, the photosynthetic electron transport chain generates damaging molecules hence leading to photooxidative stress and eventually to cell death. In this review, we summarize the mechanisms linking excessive absorption of light energy in the chloroplasts to programmed cell death in plant leaves. We highlight the importance of reactive carbonyl species generated by lipid photooxidation, their detoxification, and the integrating role of the endoplasmic reticulum in the adoption of phototolerance or cell death pathways. Finally, we invite the scientific community to standardize the conditions of excessive light treatments.

Mots clés: Arabidopsis; photosynthesis; excessive light; photooxidative stress; carotenoid; plant cell death; stress response

Domaines: Biologie végétale; Biologie cellulaire; Biochimie, Biologie Moléculaire; Biotechnologies

Stefano d'Alessandro, Inès Beaugelin, Michel Havaux. Tanned or sunburned: How excessive light triggers plant cell death. Molecular Plant, 2020, 13 (11), pp.1545-1555. ⟨10.1016/j.molp.2020.09.023⟩. ⟨hal-03303923⟩