Beta-aminobutyric acid (BABA) as a plant-produced priming agent: Biosynthesis, regulation and perception
| Responsable du projet |
Brigitte Mauch Mani
Reinhard Neier |
| Collaborateur | Damien Thevenet |
| Résumé |
Plants treated with the non-protein amino acid beta-aminobutyric
acid (BABA) develop an enhanced defensive capacity against a large
variety of biotic and abiotic stresses. Expression of such
BABA-induced resistance (BABA-IR) coincides with a faster and
stronger defense response following pathogen attack or abiotic
stress. This phenomenon has been termed “priming”. Our research
group has shown previously that there is a genetic basis for the
observed induced resistance and priming. We have isolated mutants
that allowed the dissection of the signalling pathways involved in
the phenomenon, demonstrating that BABA-IR against biotic and
abiotic stresses is based on priming of distinct defense signalling
mechanisms involving several plant hormone defense pathways.
Recently, we have been able to show that natural priming and
priming by BABA both are transgenerational phenomena, the primed
state of a plant being transferred to its descendants. Beta-amino
acids are rarely found in plants and up to now, BABA was considered
as xenobiotic substance. However, our latest results obtained in
collaboration with our colleagues from the institute of chemistry
provide clear evidence that plants do synthesize BABA and its
accumulation increases upon exposure to biotic and abiotic stress.
This exciting result upgrades BABA to the status of a potential
plant priming hormone and opens a large array of questions that
will be addressed in the present proposal: • How widespread is the
occurrence of BABA in plants? • Is endogenous BABA indispensable
for natural priming? • What is the biosynthetic pathway of BABA
production? • How is BABA biosynthesis induced and regulated? •
What is the fate of BABA in plants (catabolism, storage)? • How is
BABA perceived by the plant? To answer these questions, we will not
only rely on our longstanding experience in plant research based
techniques but we will develop novel strategies in collaboration
with colleagues from organic chemistry. As an example, the
biosynthetic pathway will be analysed classically by screening
plant mutant populations to pinpoint the synthesis and regulatory
genes of the pathway and in parallel, tools for a chemistry-based
approach using radiolabeled putative precursors will be developed
and exploited. The natural occurrence and inducibility of BABA in
plants together with its very large spectrum of efficacy for plant
priming when applied exogenously suggest that it plays an important
role in the establishment of natural priming. Priming confers
enhanced stress resistance with minimal inhibitory effects on yield
and fitness. Interestingly, the primed state is transferred to the
descendants of a primed plant. If we can identify plants that have
naturally higher levels of BABA, this trait could be exploited to
introduce a higher adaptive capacity to respond to stress into our
agricultural ecosystems. |
| Mots-clés |
induced resistance, priming, beta-aminobutyric acid |
| Type de projet | Recherche fondamentale |
| Domaine de recherche | Botanique |
| Source de financement | FNS - Encouragement de projets (Div. I-III) |
| Etat | Terminé |
| Début de projet | 1-5-2015 |
| Fin du projet | 30-4-2018 |
| Budget alloué | 678'000.00 |
| Contact | Brigitte Mauch-Mani |