Chlorophagy targets chloroplasts irreversibly damaged by photoinhibition.

Severe photoinhibition of photosystem II in Arabidopsis thaliana precedes abnormally swollen chloroplasts that chlorophagy recognizes for degradation, marking irreversibly damaged, nonfunctional organelles.

• Why it matters: It is unclear how chloroplast-level photoprotection and chlorophagy are functionally coordinated during acclimation to excess light, especially when damage becomes irreversible.
• What they did: The study combined chlorophyll fluorescence, microscopy, and genetic analyses in Arabidopsis thaliana mutants defective in NPQ or the chloroplast avoidance response, with chlorophyll fluorescence lifetime imaging plus probes for singlet oxygen and starch.
• The result: Swollen chloroplasts accumulated reactive oxygen species, lost photosynthetic function, and their formation increased in NPQ- or avoidance-defective mutants, where hyperaccumulation of nonfunctional chloroplasts was linked to necrotic cell death.

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