Azoles activate type I and type II programmed cell death pathways in crop pathogenic fungi

Area of Science:

• Agricultural Science
• Mycology
• Biochemistry

Background:

• Triazoles are crucial fungicides targeting ergosterol biosynthesis.
• Their precise fungicidal mechanisms in key plant pathogens remain incompletely understood.

Purpose of the Study:

• To elucidate the mode of action of epoxiconazole and metconazole in Zymoseptoria tritici and Magnaporthe oryzae.
• To identify the cellular processes and programmed cell death pathways involved in azole-induced fungal lethality.

Main Methods:

• Investigated azole effects on plasma membrane properties and protein localization.
• Utilized mutant studies and pharmacological treatments in vitro and in planta.
• Assessed the roles of apoptosis and macroautophagy in azole toxicity.

Main Results:

• Epoxiconazole and metconazole reduced plasma membrane fluidity, impairing F-BAR protein localization and septation.
• Azole lethality resulted from a combination of reactive oxygen species-induced apoptosis and macroautophagy.
• Inhibiting both cell death pathways abolished azole-induced fungal death.

Conclusions:

• Azole fungicides induce fungal cell death through plasma membrane disruption and dual activation of apoptosis and macroautophagy.
• Activation of these programmed cell death pathways is a common hallmark of ergosterol biosynthesis inhibitors.
• Findings inform the development of novel crop protection strategies against fungal pathogens.