APX — Solanum lycopersicum

Summary

SOLYC09G007270.3 (APX1) on tomato chromosome 9 encodes a haem peroxidase with L-ascorbate peroxidase activity, also annotated with p-coumarate 3-hydroxylase, siRNA binding, and protein kinase activities. The gene is associated with drought resistance in tomato and linked to numerous traits including fruit diameter, stem thickness, leaf weight, root volume, seedling vigor, soluble protein content, and relative chlorophyll content. It is associated with the ascorbate-glutathione cycle, xanthophyll cycle, reactive oxygen species homeostasis, hydrogen peroxide removal, and responses to excess light, heat, cold, UV-A radiation, ozone, and waterlogging. Localisation evidence places the product at the peroxisome membrane, chloroplast thylakoid membrane, stress granule, plasmodesma, and extracellular space. Studies of related genes in other species link the family to salt, heat, oxidative, and high-light stress tolerance, root development, hydrotropism, and resistance to Sclerotinia sclerotiorum.