SPS — Asparagus officinalis

Summary

A4U43_C01F5540 (SPS, AoSPS) encodes a spermidine/spermine synthase, an enzyme with both spermidine synthase and spermine synthase activities (EC 2.5.1.16) that also binds proteins. In asparagus, this gene is associated with polyamine, spermidine and spermine biosynthesis, as well as carbohydrate storage, sucrose metabolism, autotrophy, nitric oxide storage, and defence responses to bacteria. It localises to the cytosol, nucleus, plasma membrane and mitochondria. The gene has been linked to carbohydrate content, sucrose content, net photosynthetic rate, respiration rate, jasmonic acid content, high temperature stress response, disease tolerance, and salt tolerance. Phenotypic associations include drought tolerance, thermotolerance, disease resistance to Botrytis cinerea and Pseudomonas syringae, salt stress response, and root growth inhibition. Studies of related genes in other species connect it to polyamine metabolism, heat stress tolerance and cadaverine sensitivity.