Prevents accumulation of abscisic acid (ABA) after heat treatment, thus reducing thermotolerance. May be a negative regulator of the ABA signaling/synthesis pathway (PubMed:20016941). Required for defense responses against avirulent bacteria such as P.syringae pv. tomato DC3000 (avrRpt2) (Ref.5). Interacts with RPS2. Expressed in roots, leaves, flowers and siliques. Accumulates in meristematic tissues such as shoot apex and root tips, young leaf veins, stamens and stigmas of flowers, and abscission layers of young siliques. In young seedlings, present in root tips and junctions of roots and hypocotyls. Highest levels are reached in ten days old seedlings. In adult plants, confined to vasculature and hydathodes in leaves, and meristems. Also observed in floral developing organs. Induced by P.syringae pv. tomato (PubMed:17899171). Repressed by heat stress (42 degrees Celsius) but induced by low temperature (4 degrees Celsius). Slightly repressed by NaCl (PubMed:20016941). No obvious phenotype under heat stress (PubMed:20016941). Impaired resistance to avirulent bacteria P.syringae pv. tomato DC3000 (avrRpt2) (Ref.5).