Skip to main content
ISMPMI Congress 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.

Poster

Session: Session 2 Presenting Authors at Posters (Evens)

P-146 - Ralstonia solanacearum induces host polyamine synthesis via a highly conserved TALE-like effector

Thursday, July 17, 2025
13:30 - 15:15  
Location: Confex Hall 3
Effector Interference Mechanisms
Bacterial wilt disease, caused by Ralstonia solanacearum, is one of the most devastating plant diseases, affecting >200 plant species, including many crops. R. solanacearum invades host roots and vasculature where it proliferates, causing wilting and death of the plant. To manipulate its host, R. solanacearum injects RipTALs, a class of effectors related to Xanthomonas TALEs that bind to a specific sequence in the host genome and activate transcription of the downstream gene. The first characterised RipTAL, was found to exclusively activate host arginine decarboxylase (ADC) genes, encoding a key enzyme involved in polyamine (PA) biosynthesis. Remarkably, RipTALs found in all four geographically isolated R. solanacearum phylotypes all target ADC in their hosts, suggesting that ADCs have remained a conserved target since the phylotype’s divergence (~180 million years ago). We recently discovered that transcriptional activation of ADCs not only increases ADC activity and PA synthesis but also dramatically boosts PA conjugation to hydroxycinnamic acids (HCAs), up to 40-fold for some metabolites. Both PA-conjugates and HCAs have antimicrobial properties, yet R. solanacearum has the unique ability to degrade them. Our current evidence led us to the exciting hypothesis that RipTAL activation of ADCs may manipulate the host into producing antimicrobial compounds that alter the root microbiome, giving R. solanacearum a competitive growth advantage over niche competitors.