Belowground microbiota analysis indicates that Fusarium spp. exacerbate grapevine trunk disease

Area of Science:

• Plant Pathology
• Microbiology
• Viticulture

Background:

• Grapevine trunk diseases (GTDs) pose significant threats to viticulture worldwide.
• Belowground fungal microbiomes influence plant health and may be linked to GTD development.
• Understanding these associations is crucial for managing GTDs.

Purpose of the Study:

• To investigate the relationship between belowground fungal communities and GTD-affected grapevines.
• To characterize fungal communities in bulk soils, rhizospheres, and roots of symptomatic and asymptomatic vines.
• To determine the impact of fungal microbiota on GTD development.

Main Methods:

• High-throughput amplicon sequencing of the ITS region was used to analyze fungal communities.
• Samples were collected from bulk soils, rhizospheres, and roots over two years.
• Statistical analyses (PERMANOVA) were employed to assess community variations.

Main Results:

• Fungal community composition varied significantly by soil-plant compartment and sampling year.
• GTD symptomatology showed a weaker, yet significant, association with fungal communities, particularly in roots and rhizospheres.
• Fusarium spp. were enriched in symptomatic roots and rhizospheres and exacerbated disease severity when co-inoculated with other pathogens.

Conclusions:

• Belowground fungal microbiota composition is influenced by soil-plant compartments, environmental conditions, and GTD presence.
• GTD symptoms are linked to the enrichment of specific fungi like Fusarium spp., rather than just the abundance of known pathogens.
• These findings offer insights into the opportunistic pathogenesis of GTDs and potential strategies for disease management.