Biopesticide Activity from Drimanic Compounds to Control Tomato Pathogens

Area of Science:

• Agricultural Science
• Plant Pathology
• Natural Product Chemistry

Background:

• Tomato crops face significant economic losses globally due to infectious diseases caused by bacteria, fungi, and oomycetes.
• Key phytopathogens include *Clavibacter michiganensis* subsp. *michiganensis* (bacterial canker), *Pseudomonas syringae* pv. *tomato* (bacterial speck), *Fusarium oxysporum* f. sp. *lycopersici* (Fusarium Wilt), and *Phytophthora* spp. (affecting tomato and potato).

Purpose of the Study:

• To evaluate the efficacy of four drimane compounds (polygodial, drimenol, isonordrimenone, and nordrimenone) against four major tomato phytopathogens.
• To identify potential novel treatments for bacterial and fungal plant diseases affecting tomato crops.

Main Methods:

• Four drimane compounds were tested against *Clavibacter michiganensis*, *Pseudomonas syringae*, *Fusarium oxysporum*, and *Phytophthora* spp.
• Minimal Inhibitory Concentrations (MIC) were determined to quantify the antimicrobial and antimycotic activity of the compounds.

Main Results:

• Polygodial (compound 1) and synthetic nordrimenone (compound 4) exhibited potent activity against the tested phytopathogens.
• Compounds 1 and 4 showed significant inhibition against *Clavibacter michiganensis* with MIC values of 16 and 32 µg/mL, respectively.
• Both compounds demonstrated high antimycotic activity against *Fusarium oxysporum* and *Phytophthora* spp. with MIC values of 64 µg/mL.

Conclusions:

• Drimane compounds, particularly polygodial and nordrimenone, represent promising natural and synthetic alternatives for controlling major bacterial and fungal diseases in tomato.
• Further research into drimane compounds could lead to the development of novel, effective crop protection strategies against devastating plant pathogens.