Role of phospholipid signalling in plant environmental responses

• Signalling lipids can be produced by phospholipases or lipid kinases.
• Enzymes producing signalling lipids are encoded by multigenic families in plants.
• Phosphatidic acid is the best studied signalling lipid in plants.
• Phosphatidic acid is produced in response to stresses or hormonal inputs.
• Phosphatidic acid binds to proteins that control downstream transducing events.

Despite the fact that all plants follow strict developmental programmes, they also have intrinsic mechanisms to monitor the environment and activate appropriate responses at the (sub-)cellular level, facilitating adaptation to abiotic and biotic fluctuations. The functionality of plant adaptive systems always relies on the sum of signalling machineries that control their transition from the resting state. Phosphoglycerolipids play a role in such signalling mechanisms. These structural components of cell membranes can be converted into multiple bioactive lipids, but also into soluble molecules. Together they shape cell metabolism via binding to downstream protein targets, thus affecting enzymatic activities, vesicle trafficking and ion fluxes. The conversion of lipids is catalysed by the hydrolytic activity of phospholipases and by the action of lipid-kinases and lipid-phosphatases. These activities are strictly regulated in plant cells and are highly reactive to various environmental signals. While phospholipases have been shown to be essential for plant growth and adaptability, many aspects of phosphoglycerolipid signalling at the molecular level remain unknown. Here, we summarise the latest concepts and challenges associated with phosphoglycerolipid signalling in relation to environmental responses in plants.