Fungicide-induced transposon movement in Monilinia fructicola

Area of Science:

• Plant Pathology
• Molecular Biology
• Mycology

Background:

• Repeated fungicide applications with single modes of action may select for resistant pathogen strains.
• The effect of sub-lethal fungicide doses on sensitive pathogen populations remains largely unknown.

Purpose of the Study:

• To investigate the in vitro impact of sub-lethal fungicide doses on the genetic stability of Monilinia fructicola.
• To determine if continuous fungicide exposure can induce genetic changes, specifically transposon activity.

Main Methods:

• Exposed three fungicide-sensitive Monilinia fructicola isolates to varying doses of demethylation inhibitor (DMI) fungicide SYP-Z048 and quinone outside inhibitor (QoI) fungicide azoxystrobin.
• Monitored the transposition of the Mftc1 transposable element using PCR and Southern blot analysis.
• Assessed changes in the MfCYP51 promoter region following fungicide treatments.

Main Results:

• Fungicide treatments, particularly azoxystrobin and a mixture of azoxystrobin and SYP-Z048, induced Mftc1 transposon movement in two of three isolates.
• The MfCYP51 upstream promoter region was identified as a target for Mftc1 transposition in some treated isolates.
• Transposition of Mftc1 was confirmed in a separate experiment involving prolonged, sub-lethal azoxystrobin exposure.

Conclusions:

• Continuous exposure to certain fungicides can induce genetic changes, including transposon transposition, in sensitive fungal populations.
• Fungicide-induced mutagenesis warrants further investigation for potential implications under field conditions.
• The MfCYP51 gene's promoter region may be susceptible to fungicide-induced transposon activity.