Confers resistance to the incompatible pathogenic bacteria P.syringae pv. tomato DC3000 in a PR1-dependent manner. Seems not involved in abscisic acid (ABA) biosynthesis. Highly expressed in the radicle tip, lateral root primordia and tips, and the area surrounding the cotyledon hydathode of young seedlings. Accumulates upon Pseudomonas syringae infection and after treatment with systemic acquired resistance (SAR)-inducing chemicals, 1,2-benzisothiazol-3(2H)-one1,1-dioxide (BIT) and benzo-(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH). No phenotype regarding abiotic stresses. Enhanced susceptibility to the incompatible pathogenic bacteria Pseudomonas syringae pv. tomato DC3000. Belongs to the short-chain dehydrogenases/reductases (SDR) family.