Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis

Delta-1-pyrroline-5-carboxylate synthetase enzymes, which catalyse the rate-limiting step of proline biosynthesis, are encoded by two closely related P5CS genes in Arabidopsis. Transcription of the P5CS genes is differentially regulated by drought, salinity and abscisic acid, suggesting that these genes play specific roles in the control of proline biosynthesis. Here we describe the genetic characterization of p5cs insertion mutants, which indicates that P5CS1 is required for proline accumulation under osmotic stress. Knockout mutations of P5CS1 result in the reduction of stress-induced proline synthesis, hypersensitivity to salt stress, and accumulation of reactive oxygen species. By contrast, p5cs2 mutations…

• DF
  Deutsche Forschungsgemeinschaft