Nonspecific Phospholipase C NPC4 Promotes Responses to Abscisic Acid and Tolerance to Hyperosmotic Stress in Arabidopsis |
| |
| Authors: | Carlotta Peters Maoyin Li Rama Narasimhan Mary Roth Ruth Welti Xuemin Wang |
| |
| Institution: | aDepartment of Biology, University of Missouri, St. Louis, Missouri 63121;bDonald Danforth Plant Science Center, St. Louis, Missouri 63132;cKansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, Kansas 66506 |
| |
| Abstract: | Diacyglycerol (DAG) is an important class of cellular lipid messengers, but its function in plants remains elusive. Here, we show that knockout of the Arabidopsis thaliana nonspecific phospholipase C (NPC4) results in a decrease in DAG levels and compromises plant response to abscisic acid (ABA) and hyperosmotic stresses. NPC4 hydrolyzes various phospholipids in a calcium-independent manner, producing DAG and a phosphorylated head group. NPC4 knockout (KO) plants display decreased ABA sensitivity in seed germination, root elongation, and stomatal movement and had decreased tolerance to high salinity and water deficiency. Overexpression of NPC4 renders plants more sensitive to ABA and more tolerant to hyperosmotic stress than wild-type plants. Addition of a short-chain DAG or a short-chain phosphatidic acid (PA) restores the ABA response of NPC4-KO to that of the wild type, but the addition of DAG together with a DAG kinase inhibitor does not result in a wild-type phenotype. These data suggest that NPC4-produced DAG is converted to PA and that NPC4 and its derived lipids positively modulate ABA response and promote plant tolerance to drought and salt stresses. |
| |
| Keywords: | |
|
|
