Stress induces the accumulation of beta-aminobutyric acid (BABA) in plants
I. BACCELLI (1), D. Thevenet (1), A. Balmer (1), V. Pastor (1), A. Vallat (1), R. Neier (1), G. Glauser (1), B. Mauch-Mani (1) (1) University of Neuchâtel, Switzerland

Plants can be sensitized to respond faster and/or stronger to stress situations by application of the priming molecule beta-aminobutyric acid (BABA). BABA can increase resistance against a wide range of both abiotic and biotic stresses, like drought and salinity, or biotrophic and necrotrophic pathogens. This wide effectiveness is due to the fact that when plants are treated with BABA, the signaling pathway most appropriate to counteract the given stress situation can be deployed more rapidly. For instance, against Plectosphaerella cucumerina infection, BABA priming leads to an ABA-dependent enhancement of the callose response at the sites of attempted penetration, and thus to increased resistance. Here, we provide evidence that BABA, a non-protein amino acid considered a xenobiotic for more than 50 years, is actually produced by plants and regulated by stress. By using a sensitive and selective protocol developed in our laboratory and based on ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), we were able to separate BABA from its two isomers alpha (AABA) and gamma (GABA) present in plant tissues, and to quantify it. Subsequent analyses revealed that BABA is present in various plant species, including Arabidopsis and crops like maize. In addition, BABA levels were found to increase following salt stress and P. cucumerina infection. The BABA biosynthetic pathway and its regulation following stress are currently under investigation. Our results suggest that BABA is a stress hormone helping plants to better cope with stress.

Abstract Number: C15-2, P18-698
Session Type: Concurrent