Phosphatidic acid: an emerging plant lipid second messenger

Area of Science:

• Plant biology
• Molecular signaling
• Biochemistry

Background:

• Phosphatidic acid (PA) is increasingly recognized as a vital second messenger in plant cells.
• PA levels surge rapidly in response to diverse environmental and chemical stresses, including ethylene, wounding, pathogens, osmotic stress, oxidative stress, and abscisic acid.
• The rapid increase in PA signaling is counteracted by its phosphorylation to diacylglycerol pyrophosphate.

Purpose of the Study:

• To review the accumulating evidence supporting the role of phosphatidic acid as a plant stress signaling molecule.
• To highlight the signaling pathways involved in phosphatidic acid production and degradation.
• To discuss the identification of downstream targets and gene families involved in phosphatidic acid signaling.

Main Methods:

• Literature review of studies on plant signaling pathways.
• Analysis of gene cloning and characterization data for phospholipases and related enzymes.
• Identification of downstream targets through biochemical and genetic approaches.

Main Results:

• Phosphatidic acid levels increase rapidly under various stress conditions.
• Two primary signaling pathways, involving phospholipases C and D (often with diacylglycerol kinase), generate phosphatidic acid.
• Downstream targets, including protein kinases and ion channels, have been identified, indicating diverse roles for phosphatidic acid.

Conclusions:

• Phosphatidic acid is a key, rapidly responsive second messenger in plant stress signaling.
• Understanding the genes and downstream effectors of phosphatidic acid signaling is crucial for deciphering plant stress responses.
• Further research into phosphatidic acid pathways can reveal new strategies for improving plant stress tolerance.