Plays a general role in cellular responses to stress, may be by attenuating the signal produced by phospholipases. Exhibits both diacylglycerol pyrophosphate (DGPP) phosphatase and phosphatidate (PA) phosphatase activities. Substrate preference is diacylglycerol pyrophosphate > phosphatidate. PA phosphatase activity inhibited by N-ethylmaleimide with an IC(50) value of 10 mM. Strongly expressed in leaves, moderately in roots, weakly in floral hamps and flower buds, and not detected in adult flowers and seedpods. Rapid increase in response to severe radiation stress (gamma rays or UV-B). Returns to basal level 45 min after the radiation injury. Also induced by mastoparan and by the hypersensitive response elicitor harpin. In this later case, induction is also observed in the leaves adjacent to those that were infiltrated with harpin. Belongs to the PA-phosphatase related phosphoesterase family. Sequencing errors.