Fungal pathogen activity and stress-dependent responses of grapevine wood to esca and drought

These data were obtained in the research project GPR Bordeaux Plant Science at Bordeaux University and INRAE UMR 1065 SAVE laboratory. Contact: Chloé E. L. Delmas ([e-mail]), INRAE, ISVV, Bordeaux Sciences Agro, Santé et Agroécologie du Vignoble, 33140 Villenave d'Ornon, France Effect of drought and esca leaf symptoms expression on grapevine trunk and grapevine trunk pathogens (GTP), analysed in RNAseq (grape and 8 GTP), metabolomic (grape) and metabarcoding (Fungal ITS). 30-y-old grapevine plants (Vitis vinifera) cv. Sauvignon blanc, naturally infected and monitored for esca leaf symptoms for seven years, were uprooted from the vineyard in 2018 and planted in 20 L pots in a greenhouse at the INRAE Bordeaux Nouvelle Aquitaine, in Villenave d'Ornon, France (44.789256, -0.577163). Samples were collected in october 2019. RNAseq was performed at the GeT-PlaGe core facility, INRAE Toulouse (Illumina NovaSeq 6000). Metabolomic extraction and mass spectrometry was performed at MetaboHUB-Bordeaux Metabolome facility (UHPLC-LTQ-Orbitrap mass spectrometry). Metabarcoding second PCR and amplicon sequencing were performed by the Genome Transcriptome Facility of Bordeaux (Illumina Miseq). Ecophysiological data can be found in: Bortolami G, Gambetta GA, Cassan C, Dayer S, Farolfi E, Ferrer N, Gibon Y, Jolivet J, Lecomte P, Delmas CEL. 2021. Grapevines under drought do not express esca leaf symptoms. Proceedings of the National Academy of Sciences 118. DOI: 10.1073/pnas.2112825118 Paper reference: Chambard M, Cantù D, Bortolami G, Dell'Acqua N, Ferrer N, Gambetta GA, Garcia JF, Gastou P, Massonnet M, Moretti S, Petriacq P, Rochepeau A, Foulongne-Oriol M, Delmas CEL. 2025 Fungal pathogen activity and stress-dependent responses of grapevine wood to esca and drought Paper abstract: ? Biotic and abiotic stresses alter the physiology of perennial plants, with consequences for fungal endophytes and disease expression. In grapevine, one of the world's most valuable crops, drought inhibits esca disease expression, but the underlying molecular interactions between plant and fungi are unknown. ? We combined wood metatranscriptomics, metabolomics, and metabarcoding to investigate these interactions in 30-year-old grapevines and eight wood-pathogenic fungi under conditions of drought or esca leaf symptom expression. ? Both esca and drought decreased grapevine transpiration, but with different transcriptomic and metabolic signatures. Similar pathways were also activated, including the phenylpropanoid and stilbenoid synthesis pathways. These stress responses could potentially confer cross-tolerance, and elicit different fungal molecular responses. The levels of putative fungal virulence factors increased significantly under both stresses. Under drought, only the relative abundance of Phaeomoniella chlamydospora and gene expression involved in anti-oxidative mechanisms, growth, and reproduction increased. Under esca expression conditions, only the relative abundance of Fomitiporia mediterranea and gene expression involved in wood degradation, competition, detoxification, and growth increased. ? The grapevine defense mechanisms induced by drought coupled with a low transpiration rate and a low abundance and virulence of F. mediterranea may account for esca leaf symptom inhibition upon water deficit.