Phospholipid signaling under salt stress, drought, cold, or ABA. Osmotic stress, cold, and ABA activate several types of phospholipases that cleave phospholipids to generate lipid messengers (e.g., PA, DAG, and IP3), which regulate stress tolerance partly through modulation of stress-responsive gene expression. FRY1 (a 1-phosphatase) and 5-phosphatase-mediated IP3 degradation attenuates the stress gene regulation by helping to control cellular IP3 levels. PLC, phospholipase C; PLD, phospholipase D; PLA2, phospholipase A2; PA, phosphatidic acid; DAG, diacyglycerol.