STM — Cucumis sativus

Summary

CsSTM (CSA_3G221750) on cucumber chromosome 3 encodes a serine hydroxymethyltransferase (EC 2.1.2.1) with glycine hydroxymethyltransferase activity, a pyridoxal phosphate-binding enzyme. The gene is associated with carpel formation, floral whorl morphogenesis, sex determination, internode patterning, and maintenance of inflorescence meristem identity. It has been linked to shoot apical meristem development, phyllotaxy, leaf shape, plant height, fruit growth, photosynthetic rate, chlorophyll content, flowering time, and disease tolerance. Additional associations include oxidative stress response, zinc and herbicide sensitivity, root meristem development, and vascular tissue morphology. The product localises to chloroplast thylakoid, mitochondrial lumen, and apoplast, and participates in glycine biosynthesis, amino acid metabolism, and tetrahydrofolate interconversion. Studies of related genes in other species link the family to photorespiration, drought and salt tolerance, stomatal closure, and basal defence against Pseudomonas syringae.