Two novel plant cDNAs homologous to animal type-2 phosphatidate phosphatase are expressed in cowpea leaves and are differently regulated by water deficits.

Two cDNAs encoding putative phosphatidate phosphatases (PAPs) designated VuPAP-alpha and VuPAP-beta were cloned in cowpea (Vigna unguiculata L.) leaves. The predicted proteins have six membrane-spanning regions in common with animal type-2 PAPs. Unlike VuPAP-beta, VuPAP-alpha has an N-terminal transit peptide and is targeted in vitro to the chloroplasts. Gene expression of VuPAP-beta is stimulated by rapid air-desiccation of leaves and VuPAP-alpha transcripts increase during rehydration of plants exposed to drought-like conditions.