Powdery Mildew Resistance Genes in Vines: An Opportunity to Achieve a More Sustainable Viticulture

Abstract

Grapevine (Vitis vinifera) is one of the main fruit crops worldwide. In 2020, the total surface area planted with vines was estimated at 7.3 million hectares. Diverse pathogens affect grapevine yield, fruit, and wine quality of which powdery mildew is the most important disease prior to harvest. Its causal agent is the biotrophic fungus Erysiphe necator, which generates a decrease in cluster weight, delays fruit ripening, and reduces photosynthetic and transpiration rates. In addition, powdery mildew induces metabolic reprogramming in its host, affecting primary metabolism. Most commercial grapevine cultivars are highly susceptible to powdery mildew; consequently, large quantities of fungicide are applied during the productive season. However, pesticides are associated with health problems, negative environmental impacts, and high costs for farmers. In paralleled, consumers are demanding more sustainable practices during food production. Therefore, new grapevine cultivars with genetic resistance to powdery mildew are needed for sustainable viticulture, while maintaining yield, fruit, and wine quality. Two main gene families confer resistance to powdery mildew in the Vitaceae, Run (Resistance to Uncinula necator) and Ren (Resistance to Erysiphe necator). This article reviews the powdery mildew resistance genes and loci and their use in grapevine breeding programs.

Secondary and primary metabolites reveal putative resistance-associated biomarkers against Erysiphe necator in resistant grapevine genotypes

“…Considering all these aspects, it seems that the level of resistance (partial or total) of the loci is more important than their numbers. The level of resistance is referred to as “total” when there are greatly suppressed symptoms or no observable symptoms of infection at all and “partial” when there is a decrease in symptoms but not a complete disappearance ( Julius Kühn-Institut, 2022 ; Sosa-Zuniga et al., 2022 ). This is corroborated in our study by the assessment of the OIV-455 descriptor at 7 days after the artificial infection ( Supplementary Table 1 ).…”

“… The levels of resistance described in the table: Total = greatly suppressed symptoms or the absence of visible symptoms; Partial = in cases where the symptomatology decreases without disappearing completely ( Sosa-Zuniga et al, 2022 ; Julius Kühn-Institut, 2022 ). …”

“…To date, 17 grapevine powdery mildew resistance loci have been identified and described (Sosa-Zuniga et al, 2022); a descriptive list of them is available online (www.vivc.de/loci). It is important to note, however, that the presence of only one gene or locus, even if it has a large effect, can favor the selection of fungus isolates capable of overcoming resistance (McDonald and Linde, 2002).…”

“…Despite the broad interest in more sustainable agriculture, metabolomics studies performed so far have focused on understanding the mechanism of grapevine defense against downy mildew, while only a limited number of investigations focused on E. necator ( Pimentel et al., 2021 ). Recent studies have shown the mechanisms underlying the synergy between metabolomics and various omics approaches ( Maia et al., 2020 ; Pimentel et al., 2021 ; Sosa-Zuniga et al., 2022 ; Yin et al., 2022 ), the metabolic differences in the composition of the berries and leaves in several grapevine cultivars ( Atak et al., 2021 ; Rienth et al., 2021 ) as well as control of the pathogen ( Gur et al., 2022 ).…”

Semi-Targeted Profiling of the Lipidome Changes Induced by Erysiphe Necator in Disease-Resistant and Vitis vinifera L. Varieties

“…Moreover, the different genotypes had different phenotypic responses to the pathogen. When there are considerably suppressed symptoms or no detectable symptoms of infection at all, the level of resistance is referred to as “total”, and when there is a decrease in symptoms but no complete disappearance, the level of resistance is referred to as “partial” [ 35 , 36 ]. The OIV-455 descriptors indicated BC4 as a genotype with very high resistance, which is in accordance with the studies of [ 20 , 37 ], which classified BC4 as a genotype with total resistance.…”