P5CS — Sorghum bicolor

Summary

SORBI_3009G160100 (SbP5CS) on sorghum chromosome 9 encodes a bifunctional enzyme with glutamate 5-kinase (EC 2.7.2.11) and glutamylphosphate reductase (EC 1.2.1.41) activities, catalyzing the first two steps of proline biosynthesis. The gene is associated with proline metabolism, the ascorbate-glutathione cycle, and responses to desiccation, salinity, oxidative stress, and abscisic acid. It is linked to cellular water homeostasis, water transport, root development, embryo development, and the transition from vegetative to reproductive phase. The protein localizes to the cytoplasm, mitochondria, Golgi complex, and plasmodesmata. SbP5CS is associated with grain yield, grain filling period, water use efficiency, photosynthetic rate, respiration rate, stay green, root length and dry weight, cell membrane stability, and proline content. Studies of related genes in other species link the P5CS family to drought, salt, and osmotic stress tolerance, as well as root elongation and flowering time.