Mycobiome Simplification in Wheat Is Associated With the Pathogen Parastagonospora nodorum

Area of Science:

• Plant pathology
• Microbial ecology
• Agricultural science

Background:

• Plant mycobiomes are crucial for plant health.
• The impact of biotic stressors, like pathogen infection, on mycobiome assembly is not well understood.

Purpose of the Study:

• To investigate how inoculating wheat (Triticum aestivum L.) with the fungal pathogen Parastagonospora nodorum affects its foliar mycobiome.
• To understand the implications for plant health and agricultural interventions.

Main Methods:

• Field inoculation trials with four wheat cultivars across two North Carolina sites.
• Utilized ITS amplicon metagenomics to analyze wheat mycobiome richness, composition, and structure.

Main Results:

• Parastagonospora nodorum inoculation reduced fungal richness by up to 38.5%.
• Foliar fungal networks became simplified, with fewer taxa and associations.
• Increased P. nodorum abundance correlated with a higher proportion of pathogens due to the loss of non-pathogenic fungi.

Conclusions:

• Pathogen infection significantly shapes mycobiome assembly in wheat.
• Reduced fungal diversity and network complexity were more pronounced in susceptible cultivars and under favorable conditions for the pathogen.
• Findings have implications for disease management and developing mycobiome-based agricultural interventions.