terclim by ICS banner
IVES 9 IVES Conference Series 9 Exogenous dsRNA applications to identify novel candidate susceptibility genes to downy mildew

Exogenous dsRNA applications to identify novel candidate susceptibility genes to downy mildew

Abstract

One of the major threats to viticulture is represented by fungal pathogens. Plasmopara viticola, an oomycete causinggrapevine downy mildew, is one of the principal causes of grape production losses. The most efficient management strategies are represented by a combination of agronomical practices, fungicides’ applications, and use of resistant varieties. Plant resistance is conferred by the presence of resistance (R) genes. Opposed to them, susceptibility (S) genes are encoded by plants and exploited by pathogens to promote infection. Loss or mutation of S genes can limit the ability of pathogens to infect the host. By exploiting post-transcriptional gene silencing, known as RNA intereference (RNAi), it is possible to knock-down the expression of S genes, promoting plant resistance. Gene silencing is induced upon exogenous application of dsRNA, which can interfere with protein synthesis. With the aim of identifying new candidate genes to be employed in breeding programs, three novel candidate S genes to downy mildew, VviLBDIf7, VviAS1 and VviB3, have been identified. Candidates’ validation was carried out through RNAi on the susceptible cultivar Pinot noir. Disease severity was estimated by experimental inoculation of P. viticola on leaves sampled at different timepoints after the treatment with dsRNA, while gene expression was evaluated by real time RT-PCR. Successful downregulation of candidate genes resulted in a significant reduction of plants susceptibility to downy mildew, suggesting our candidates as downy mildew S genes, leading to the possibility of employing an RNAi-based strategy as a more sustainable alternative to conventional management strategies.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Elisabetta Sergi1*, Giuliana Maddalena1, Valentina Ricciardi1, Demetrio Marcianò1, Beatrice Lecchi1, Osvaldo Failla1, Silvia Laura Toffolatti1, Gabriella De Lorenzis1

1 Affliliation Department of Agricultural and Environmental Sciences, via G. Celoria 2, 20133 Milan (Italy)

Contact the author*

Keywords

S genes, RNAi, gene silencing, Plasmopara viticola, Vitis vinifera

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

New antibacterial peptides produced by Saccharomyces cerevisiae responsible for the inhibition of malolactic fermentation

In winemaking, several antimicrobial peptides (AMPs) produced by different strains of Saccharomyces cerevisiae were found to be responsible for the inhibition of malolactic fermentation (MLF) carried out by some strains of Oenococcus oeni. However, only two AMPs produced by one of the yeast strains studied were totally identified and their mechanism of action was described. In an attempt to identify new AMPs, a 5-10 kDa peptidic fraction produced by an oenological strain of S. cerevisiae and previously shown to strongly inhibit MLF carried out by a strain of O. oeni was further purified.

Development of a semi-controlled setup for manipulating drought and heat stress in open field trials

Drought and heat stress will pose challenges for the future of viticulture and wine quality, as grapevine biological processes are pushed beyond their optimum conditions. Efforts are increasing to study and predict the effects of drought spells and heatwaves on grapevine physiology and resulting harvest quality. This calls for the development of adequate systems to induce and manipulate the required stress, especially in open field trials where conditions are more difficult to control. We present a semi-controlled system for studying drought and heat stress in grapevine in the field.

The role of the landscape as a component of the terroir in Spain (DO Somontano, NE Spain)

The components and methodology for characterization of the terroir in Spain have been described by Gómez-Miguel et al. (2003), Sotés et al. (2003), taking into account the full range of environmental factors (i.e: climate, vegetation, topography, soils, altitude, etc.),

What is the best time to harvest grapes destined for withering? Ripeness and dehydration length affect phenolic composition of Nebbiolo grapes

Sfursat di Valtellina is a DOCG reinforced wine produced in Valtellina from partially withered red grapes of Vitis vinifera L. cv. Nebbiolo. The grape ripeness degree and the dehydration process strongly influence the physicochemical characteristics of grapes [1, 2, 3]. In particular, grape skin and seeds contain several classes of phenolic compounds strictly associated with red wine quality, which are significantly affected by these factors [4]. The aim of this research is to assess the combined influence of different ripeness levels and withering rates on the standard chemical composition and phenolic profile of winegrape in order to provide new insights and approaches to the management of withering, searching for the valorization of grape potentialities.

Enological impact of vineyard application of methyl jasmonate–loaded chitosan nanoparticles on ethanol reduction and wine quality preservation

Viticultural practices aimed at producing lower‑alcohol wines have traditionally focused on reducing sugar accumulation in grapes through canopy management techniques—such as early leaf removal or shading—which limit photosynthetic activity and delay ripening (Palliotti et al., 2014).