N6-methyladenine DNA modification modulates pathogen virulence in nematodes

Area of Science:

• Epigenetics
• Molecular Biology
• Plant Pathology

Background:

• N6-methyladenine (6 mA) regulates gene expression under stress.
• The role of 6 mA in pathogen virulence is largely unknown.
• Root-knot nematodes (RKNs) are significant agricultural pests.

Purpose of the Study:

• To investigate the occurrence and genomic distribution of 6 mA in RKNs.
• To identify and characterize 6 mA demethylases in RKNs.
• To assess the role of 6 mA demethylases in RKN virulence and plant-nematode interactions.

Main Methods:

• Genomic mapping of 6 mA across 17 nematode isolates.
• Identification and characterization of 6 mA demethylases (MiNMAD-1, MiNMAD-2).
• Host-induced gene silencing (HIGS) of minmad-1 and assessment of plant resistance.

Main Results:

• 6 mA is widespread in nematodes with a conserved GAG motif but species-specific patterns.
• Enrichment of 6 mA in transposable elements differs between polyploid and diploid RKNs.
• Knockdown of minmad-1 reduced RKN virulence gene expression and increased plant resistance.

Conclusions:

• 6 mA demethylase (MiNMAD-1) is a key epigenetic regulator of RKN virulence.
• 6 mA epigenetic regulation impacts nematode parasitic stage gene expression.
• Targeting 6 mA demethylases offers potential for sustainable RKN control strategies.