APX4 — Solanum tuberosum

Summary

PGSC0003DMG400006175 (APX4) on potato chromosome 1 encodes an L-ascorbate peroxidase (EC 1.11.1.7), a haem peroxidase of the Ccp1-like family with confirmed L-ascorbate peroxidase, lactoperoxidase and general peroxidase activities, and heme-binding capability. The gene is associated with the ascorbate-glutathione cycle, cellular response to oxidative stress, nonphotochemical quenching, chlorophyll a biosynthesis, GABA shunt, proline and phosphate metabolism, S-nitrosylation, malate secretion, wound healing, skin development, and fermentation. Its product localises to the peroxisome membrane, chloroplast thylakoid membrane, stroma, mitochondria, and general membrane compartments. APX4 is associated with drought tolerance and sensitivity, leaf water potential, relative water content, chlorophyll content, photosynthetic rate, quantum yield, water use efficiency, stomatal resistance, transpiration rate, plant height, root length and thickness, ear length, starch content, cell membrane stability, and callus induction. Studies of related genes in other species connect the family to leaf dry weight, leaf area index, shoot dry weight, proline and carotenoid content, fruit size, and sugar content.