Characterization of Grapevine Wood Microbiome Through a Metatranscriptomic Approach

Area of Science:

• Plant Pathology
• Microbiology
• Viticulture

Background:

• Grapevine trunk diseases cause significant yield loss and plant death in viticulture globally.
• Hoja de malvón (HDM) is a complex disease affecting Argentinian and Uruguayan grape production, with poorly understood fungal roles and microbial interactions.

Purpose of the Study:

• To characterize the grapevine wood microbiome composition using metatranscriptomics.
• To understand microbial interactions in relation to hoja de malvón (HDM) onset in Vitis vinifera cv. Malbec.

Main Methods:

• Metatranscriptomic analysis of grapevine wood from symptomatic and asymptomatic field-grown Vitis vinifera cv. Malbec.
• Analysis of microbiome composition, diversity (alpha diversity, rank-abundance curves), and interkingdom interactions via co-occurrence networks.

Main Results:

• The grapevine wood microbiome was primarily composed of Dothideomycetes and Actinobacteria.
• Symptomatic plants showed higher levels of Basidiomycota, specifically Arambarria destruens and Phellinus laevigatus, and reduced microbial evenness.
• Distinguishing symptomatic from asymptomatic plants based solely on HDM pathogen presence or abundance was not feasible.

Conclusions:

• Microbial evenness is reduced in Vitis vinifera plants exhibiting foliar symptoms of HDM.
• While specific fungi like Arambarria destruens and Phellinus laevigatus were more abundant in symptomatic plants, they were not definitive markers for HDM.
• The generated molecular data provides a foundation for developing targeted quantification methods for specific microbial taxa in grapevine health assessments.