PSBA — Arabidopsis thaliana

Summary

ATCG00020, also known as PSBA, encodes the photosystem II reaction center protein A (D1 protein) in Arabidopsis thaliana. This chloroplast-encoded protein exhibits oxygen evolving activity, chlorophyll binding, electron transfer activity, and mRNA binding. It is localized to the photosystem II complex, chloroplast thylakoid membrane, and plastid. PSBA is associated with photosynthetic electron transport in photosystem II, photosystem II assembly, photoprotection, heat dissipation, dark adaptation, and plastid gene expression. The gene is linked to chlorophyll breakdown, carotenoid anabolism, and translation initiation. Associations with agronomically relevant traits include leaf thickness, herbicide sensitivity and resistance (notably the A251V variant), quantum yield, and light intensity response. PSBA is also connected to photosystem II function and light response, with natural variation observed across multiple Arabidopsis accessions.