PubMed · 2026-04-22
Scientists discovered how a soil bacterium that causes devastating wilting disease in tomatoes and peppers disarms plant defenses: it injects a protein called RipG6 that hijacks the plant's own cellular recycling system to destroy a key immune signaling component.
RipG6 suppresses plant immune responses only when its F-box motif is intact, confirming it works by hijacking the plant's ubiquitin-proteasome protein-degradation machinery.
RipG6 directly interacts with and reduces the stability of a tomato immune kinase (RLCK-VIII-6), effectively dismantling a plant defense signaling component.
Closely related versions of the targeted kinase in wild tobacco and thale cress both function as positive regulators of plant immunity, suggesting this is a broadly conserved defense target across plant species.
