Esca-affected grapevine leaf metabolome is clone- and vintage-dependent

Area of Science:

• Plant pathology
• Viticulture
• Metabolomics

Background:

• Esca is a complex grapevine trunk disease with variable foliar symptoms influenced by environmental, physiological, and genetic factors.
• Previous research indicated clone-dependent esca expression in Chardonnay, with distinct year-dependent metabolite fingerprints.
• Understanding clone-specific disease expression is crucial for managing grapevine health.

Purpose of the Study:

• To investigate if clone-dependent esca expression occurs in Trousseau, a highly susceptible cultivar.
• To analyze year-dependent variations in symptom expression and their potential link to environmental factors like rainfall.
• To confirm clone-dependent metabolic responses in Trousseau using metabolomic analysis.

Main Methods:

• Field study in the Jura vineyard (France) with Trousseau clones 1004 and 1026 over 2017-2018.
• Observation and recording of esca foliar symptom incidence and prevalence.
• Metabolomic analysis of green leaves from diseased vines, including those without visible symptoms.

Main Results:

• Year-dependent variation in esca symptom expression was observed in Trousseau, potentially linked to rainfall.
• Clone 1026 exhibited a higher incidence of disease expression compared to clone 1004, indicating differential susceptibility.
• Metabolomic profiles of asymptomatic leaves from diseased Trousseau vines confirmed clone-dependent metabolic responses, distinct from Chardonnay.

Conclusions:

• Clone-dependent esca expression is not exclusive to Chardonnay and occurs in Trousseau.
• Trousseau clone 1026 appears more susceptible to esca than clone 1004.
• Metabolomic analysis provides insights into the underlying biochemical mechanisms of clone-specific disease response in grapevines.