CP22 — Pisum sativum

Summary

PSAT5G087360 (CP22, also known as PsCP22, NPQ4, PSBS, PsNPQ4, PsPSBS) on chromosome 5LG3 of garden pea (Pisum sativum) encodes a chlorophyll a-b binding protein that localises to the photosystem II antenna (LHCII) and thylakoid membranes. The product possesses chlorophyll, xanthophyll and phosphoprotein binding activities, as well as serine-type peptidase activity and autophagy adaptor activity. The gene is associated with responses to high light intensity, red and blue light, de-etiolation, thylakoid membrane organisation, protein breakdown and autophagy-related vacuolar targeting. It is linked to photosynthetic rate, photochemical quenching, electron transport rate, photosystem II supercomplex stability and repair, photoprotection, excess energy dissipation, growth under fluctuating light, and photooxidative damage resistance. Associations also include carotenoid, chlorophyll and protein content, reactive oxygen species homeostasis, circadian rhythm, thermotolerance, and susceptibility to two-spotted spider mite. Studies of related genes in other species link the family to non-photochemical quenching, energy dissipation, jasmonic acid production, defence against herbivores, drought tolerance, and chloroplast avoidance movement.