A Ralstonia solanacearum effector regulates plant cell death by disrupting the homeostasis of the BPA1-ACD11 complex

mBio, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

ABSTRACT Effectors secreted by phytopathogenic bacteria can suppress ETI responses induced avirulence effectors, thereby overcoming crop resistance. However, the detailed mechanisms remain largely unknown. We report that effector RipD from Ralstonia solanacearum regulates plant cell death in a protein abundance-dependent manner. targets Arabidopsis BPA1, which directly interacts with key negative regulator ACD11. competes ACD11 for binding to leading selective degradation of BPA1 via autophagy, sparing A lower dose promotes but leads accumulation, inhibiting RipAA-induced death. Conversely, higher levels degrade both and ACD11, resulting autophagy-dependent Visualization delivery R. indicated it reaches sufficient promote accumulation inhibit Our study reveals novel mechanism an inhibits and, first time, highlights critical role abundance its function. IMPORTANCE infects major economic crops, notably tomato, potato, tobacco, substantial yield reductions losses. This pathogen utilizes various type III effectors host resistance, often weakened or lost underlying Here, we reveal BPA1-ACD11 complex, is involved immunity homeostasis dose-dependent manner competitively activating modulating Importantly, visualization analysis revealed amount into cells Avr effector-induced time dosage, deepening understanding how suppresses ETI-related providing guidance resources breeding bacterial wilt

Language: Английский

The disordered effector RipAO of Ralstonia solanacearum destabilizes microtubule networks in Nicotiana benthamiana cells.

Molecules and Cells, Journal Year: 2024, Volume and Issue: unknown, P. 100167 - 100167

Published: Dec. 1, 2024

Ralstonia solanacearum causes bacterial wilt, a devastating disease in solanaceous crops. The pathogenicity of R. depends on its type III secretion system, which delivers suite effectors into plant cells. disordered core effector RipAO is conserved across species and affects immune responses when transiently expressed Nicotiana benthamiana. Specifically, impairs pathogen-associated molecular pattern-triggered reactive oxygen production, an essential defense mechanism. fused to yellow fluorescent protein initially localizes filamentous structures, resembling the cytoskeleton, before forming large punctate aggregates around nucleus. Consistent with these findings, tubulin alpha 6 (TUA6) beta-1 (TUB1), building blocks microtubules, were identified as putative targets immunoprecipitation mass spectrometry analyses. In presence RipAO, TUA6-labeled microtubules fragmented puncta, mimicking effects oryzalin, microtubule polymerization inhibitor. These corroborated N. benthamiana transgenic line constitutively expressing GFP-labeled TUA6, where reduced density stability at accumulation level that did not induce aggregation. Moreover, oryzalin treatment further enhanced RipAO's impairment ROS suggesting disrupts networks via association tubulins, leading suppression. Further research interaction network will enhance our understanding strategies subvert immunity.

Language: Английский