Small Molecule Modulators as a Means to Control Tomato Bacterial Canker
Small molecule modulators of Clavibacter michiganensis subsp. michiganensis (Cmm) as a means to control tomatobacterial canker.
Current efforts to control tomato cankers rely heavily on copper bactericides and antibiotics. These methods have significant limitations in that they exhibit limited efficacy in treatment and may promote pathogen resistance. Common strategies for controlling tomato bacterial canker mainly rely on the use of clean seed, healthy transplantation, and crop rotation. Additionally, once the canker disease is established in a field or greenhouse, chemical treatment with copper-based bactericides or antibiotics has limited effect in reducing the disease pressure. Meanwhile, the development of bactericide resistance in plant pathogenic bacteria is increasing. Therefore, novel chemicals with unique targets or target pathways are required for the management of tomato bacterial canker.
Researchers at The Ohio State University, led by Dr. Gireesh Rajashekara, identified 12 compounds from a high-throughput screening of more than 4,000 molecules for activity against the tomato bacterial pathogen, Clavibacter michiganensis subsp. michiganensis (Cmm). During evaluation, a screening was conducted to determine which compounds effectively killed multiple Cmm strains as well as Bacillus subtilis. The 12 most potent novel molecules were prioritized based on the total score evaluated in the secondary screen and their ability to reduce the pathogen infection in planta. Based on their potency and specificity, the structures of these molecules provide chemical scaffolds for developing Cmm-specific novel bactericides to control this bacterial disease. Importantly, the majority of the candidate compounds showed no phytotoxcity towards either tomato or Arabidopsis.