Esca complex grapevine trunk disease leads to cell wall changes in asymptomatic berries

ISHS Secretariat
Esca complex grapevine trunk disease leads to cell wall changes in asymptomatic berries

My PhD research work focuses on changes in grape (Vitis vinifera) berries upon fungal infection. Many fungi, such as Botrytis cinerea, Erysiphe necator, and Esca complex trunk disease, cause major economic damage for the viticulture economy and wine production industries. Different species of pathogens utilize diverse approaches for infection, leading to specific alterations in the affected host. In addition, diverse cultivars have different levels of susceptibility to these pathogens. During my research, I explored changes regarding the metabolisms of volatiles and the cell wall. Using metabolic profiling techniques, such as gas-chromatography or comprehensive microarray polymer profiling, I sought to establish a putative model of the role of the cell wall during infection. I will correlate my model with the susceptibility/tolerance level of different cultivars. The metabolic data will be supported by transcriptomic data, using techniques such as RNA sequencing and real time PCR. Together, this data will provide a model of host-pathogen interactions under different scenarios. To study B. cinerea infection, two Portuguese cultivars were selected: ‘Trincadeira’ (highly susceptible) and ‘Syrah’ (tolerant). The infection was followed from green to ripe grapes, with ‘Trincadeira’ exhibiting heavy symptoms of infections already at the green stage. For E. necator, the susceptible cultivar ‘Carignan’ was selected at the green and the veraison developmental stages, when the pathogen had a preference for chlorophyll rich tissues. For the Esca analysis, the grapes were collected from vines with symptomatic and asymptomatic “tiger-stripe” leaves. An overall analysis of cell wall polymers in the three circumstances showed different cell wall alterations, with B. cinerea leading to pectin degradation and extensin accumulation. E. necator caused callose deposition, and Esca reduced rhamnogalacturonan I arabinan branches, as well as increased glucose monomers. This development needs further study to understand the complex interactions. The wine sector has a growing need to understand these diseases and cultivar resilience to implement environmentally sustainable strategies and reduce the use of dangerous pesticides.

Helena Santos won the ISHS Young Minds Award for the best poster presentation at the XI International Symposium on Grapevine Physiology and Biotechnology, which was held virtually in South Africa in October-November 2021.

Helena Santos, BioISI – Instituto de Biosistemas e Ciências Integrativas, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal, e-mail:

The article is available in Chronica Horticulturae

grapevine physiology
Young Minds Award Winners