Synthetic primer of plant defence was produced in plants all along

Last updated: 4 Jan, 2017

For years, researchers have applied beta-aminobutyric acid (BABA) to plants to prime them to respond to stresses such as infection or drought. BABA was believed not to be produced by plants, but a team of Swiss researchers developed a powerful new detection method to show that BABA is indeed present in a variety of plant species, a new paper in New Phytologist reports.

Plants are exposed to many environmental stresses, relying on their disease and stress resistance responses to help them survive. These defence systems can be primed in advance by applying various chemicals, including BABA, to the plants, which intensifies their response to a subsequent threat. Until recently BABA was not thought to be produced by plants, but when a BABA-specific receptor was discovered in the model plant Arabidopsis thaliana, Damien Thevenet and colleagues began to suspect that this might not be the case.

Thevenet and colleagues developed a sensitive method that was able to distinguish BABA from other forms of the same molecule, alpha- and gamma-aminobutyric acid (AABA and GABA), which also function in stress responses. They found that BABA was produced by a variety of plant species, including Arabidopsis, maize (Zea mays), wheat (Triticum aestivum), Chinese cabbage (Brassica rapa) and the moss Physcomitrella patens, albeit in much lower amounts than AABA and GABA.

BABA is known to prime plants to respond to a wide range of stresses. Thevenet et al. showed that plants exposed to infection, submergence in water, and high levels of salt all produced higher levels of BABA, boosting the plant’s defence systems and helping it to survive these conditions.

The results of this study call for a re-think of previous research into the BABA-primed plant defence responses, and open new avenues of investigation that can help us to unravel how priming takes place and better understand plant resilience in the future.

Read the paper: Thevenet, D., Pastor, V., Baccelli, I., Balmer, A., Vallat, A., Neier, R., Glauser, G. and Mauch-Mani, B. (2016), The priming molecule β-aminobutyric acid is naturally present in plants and is induced by stress. New Phytologist. doi: 10.1111/nph.14298

Image: A beta-aminobutyric acid molecule. Credit: public domain.

Sarah Jose
@JoseSci