Grapevines under drought do not express esca leaf symptoms
Giovanni Bortolami, Gregory A. Gambetta, Cédric Cassan, Silvina Dayer, Elena Farolfi, Nathalie Ferrer, Yves Gibon, J. Jolivet, Pascal Lecomte, Chloé E. L. Delmas
Abstract
Significance The world is witnessing a sharp increase in perennial plant dieback. The hypothesized cause is that environmental stresses such as drought are interacting with pathogens fueling plant decline. Global viticulture has seen similar decreases in fruit yield and vine longevity. One of the hypothesized causes is a synergy between drought and the grapevine vascular disease esca, for which there is no known curative treatment. In sharp contrast to this theory, our study demonstrates that drought completely suppresses esca leaf symptoms, and although esca and drought both alter plant water transport and carbon balance, they do so in completely distinct ways. This understanding reveals the complexity and unpredictability of the stress interactions thought to drive plant mortality.