APX — Cucumis sativus

Summary

CsAPX (CSA_1G479610) on cucumber chromosome 1 encodes a haem peroxidase with L-ascorbate peroxidase activity (EC 1.11.1.11), belonging to the Ccp1-like and peroxidase_I families. The gene is associated with ascorbate metabolism, the xanthophyll cycle, upregulation of photosynthesis, reactive oxygen species homeostasis, and responses to abiotic stimuli. It is linked to traits such as leaf chlorophyll content, carotene content, biomass yield, seedling vigor, shoot and root fresh and dry weight, cob diameter and length, bacterial blight disease resistance, viral disease response, aphid response, hydrogen peroxide content, and IAA content. The encoded protein localises to the peroxisome membrane, chloroplast thylakoid membrane, and mitochondria. Studies of related genes in other species connect the family to oxidative stress tolerance, thermotolerance, drought resistance, and pathogen defense.