Description du projet
Aperçu moléculaire de l’immunité des plantes
Les réponses immunitaires des plantes contre les agents pathogènes sont orchestrées par l’acide salicylique (AS), une hormone qui ressemble chimiquement à l’aspirine et qui s’accumule pour établir une immunité locale et plus large. L’AS déclenche des changements dans des milliers de gènes, privilégiant les réponses immunitaires plutôt que la croissance normale. Financé par le Conseil européen de la recherche, le projet IMMUNE-EXPRESS vise à définir le mécanisme d’action de l’AS sur l’activité des gènes. Les travaux se concentreront sur la protéine NPR1, qui contrôle l’expression des gènes et le rôle de l’AS. Étant donné que les pratiques agricoles utilisent des mimétiques de l’AS et des composés pour activer la signalisation de l’AS afin de protéger les plantes et les cultures contre les maladies, les résultats de l’étude contribueront à améliorer la santé des plantes et les stratégies agricoles.
Objectif
Plants are continuously exposed to a wide variety of pathogenic attackers that cause major crop losses to agriculture worldwide. Unlike vertebrates that use specialized immune cells to detect non-self, each individual plant cell is thought to be capable of launching an effective immune response. Plant immune responses are largely orchestrated by the immune hormone, salicylic acid (SA), which accumulates upon infection and establishes both local and broad-spectrum systemic immunity. SA induces the reprogramming of thousands of genes to prioritize immune responses over normal cellular growth functions. Consequently, commercial SA mimics have been developed and applied as crop protection agents worldwide. Nonetheless, how SA reprograms the transcriptome remains poorly understood yet is critical for the design of improved crop protection strategies that avoid plant growth and yield penalties.
SA-induced transcription reprogramming is largely mediated by NPR1, a master coactivator of gene expression. We recently reported that direct perception of SA by a Cullin3-RING ubiquitin ligase (CRL3) in the nucleus regulates the transcriptional activity of NPR1 by targeting it for degradation via the ubiquitin proteasome system (UPS). Our latest data suggest that ubiquitination by CRL3 and other ubiquitin chain modifying enzymes may be processive and establishes a transcriptional timer for NPR1 activity. This proposal aims to understand the flexibility and necessity of this transcriptional ubiquitin timer in meeting cellular demands for dynamic gene expression during SA-mediated plant immune responses. Moreover, we will uncover the full substrate ranges of SA-induced ubiquitin ligases and their post-translational regulation to precisely chart the intimate roles the UPS plays in coordinating plant immune gene expression. Importantly, these findings will provide novel chemical and genetic targets that can be harnessed in future crop improvement strategies.
Champ scientifique
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
EH8 9YL Edinburgh
Royaume-Uni