Propionic Acid Signalling Modulates Stomatal Opening and Drives Energy Metabolism to Enhance Drought Resistance in Wheat (Triticum aestivum L.).

Drought stress caused by global climate change severely imperils crop productivity and increases environmental deterioration. Wheat (Triticum aestivum L.) is an important worldwide food crop. Drought resistance in wheat encompasses functional gene transcription, metabolism, hormone signalling, and protein modifications. However, the underlying mechanisms by which these regulatory responses are coordinated remain unknown. Herein, we report a drought-resistance network in which wheat triggers a dynamic metabolic flux conversion from propionic acid (PA) to the tricarboxylic acid (TCA) cycle through beta-oxidation of fatty acids and stimulates crosstalk of various hormonal signals. It is also possible that P300/CREB regulates histone acetylation to confer drought resistance in wheat. Exogenous PA drives the TCA cycle and glycolysis and promotes stomatal closure through hormones crosstalk. From Aegilops tauschii Cosson (the diploid progenitor of common wheat) to wheat, this novel PA function serves as a survival strategy against environmental changes, and was validated in wheat field experiments. Our results highlight a new survival strategy that triggers the comprehensive and systemic effects of functional genes, metabolomics, hormone signalling, and protein modification on drought resistance to provide novel insights into improving the agroecological environment.