In a common‑garden study of 23 Vitis vinifera cultivars, the authors linked higher white‑rot necrosis and elevated hemicellulose coupled with reduced extractives to increased susceptibility to Esca disease. Glycosylated phenylpropanoids accumulated in symptomatic vines, while the composition of healthy‑wood endophytic microbial communities remained unchanged across cultivars, indicating that wood degradability and metabolic response drive susceptibility more than microbial factors.