Associated links among mtDNA glycation, oxidative stress and colony sectorization in Metarhizium anisopliae

Area of Science:

• Mycology
• Cell Biology
• Biochemistry

Background:

• Filamentous fungi deterioration on artificial media often manifests as sterile sectors.
• Previous work linked sectorization in Metarhizium anisopliae to intracellular reactive oxygen species (ROS).

Purpose of the Study:

• To investigate the role of oxidative stress and DNA glycation in fungal sectorization.
• To elucidate the mechanisms underlying fungal colony deterioration.

Main Methods:

• Quantification of intracellular ROS in stable and unstable fungal strains.
• Analysis of mitochondrial and genomic DNA for glycation.
• Assessment of mitochondrial membrane potential.
• Induction of sectorization and morphological changes using hydrogen peroxide (H(2)O(2)).

Main Results:

• Hydrogen peroxide (H(2)O(2)) accelerates sectorization.
• Stable M. anisopliae strains clear intracellular ROS faster than unstable ones.
• Mitochondrial DNA, but not genomic DNA, showed non-enzymatic glycation of deoxyguanosine in sectors.
• Mitochondria in sector cells exhibited decreased membrane potential, indicating functional loss.
• H(2)O(2) treatment replicated sectorial glycation patterns and morphological changes.

Conclusions:

• Fungal sectorization is an aging-related impairment driven by oxidative stress.
• ROS-induced DNA glycation in mitochondria contributes to fungal colony deterioration.
• Mitochondrial DNA's AT bias may be an adaptation to mitigate glycation consequences.