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…

High density balsamic vinegar: application of stable isotope ratio analysis to determine watering down.

Aceto balsamico di Modena IGP (ABM) is an Italian worldwide appreciated PGI (Protected Geographical Indication) vinegar,  obtained from cooked and/or concentrated grape must (at least 20% of the volume), with the addition of at least 10% of wine vinegar and a maximum 2% of caramel for color stability (EU Reg. 583/ 2009).

Water status, nitrogen status and leaf area/ crop ratio effect on aromatic potential of vitis viniferaberries : example of Sauvignon blanc

Les effets de l’état hydrique et de l’alimentation en azote sur le potentiel aromatique des raisins de Sauvignon blanc ont été mesurés sur des vignobles du Bordelais. Les déficits hydriques ont été caractérisés par le potentiel tige déterminé en milieu de journée ΨTmin)­. L’alimentation en azote a été étudiée à partir d’une zone carencée en azote. Une part de cette zone a été supplémentée avec de l’azote minéral.

Use of membrane ultrafiltration technology to achieve protein stabilisation of white wine

AIM: Proteins in white wine can cause cloudiness or haze after bottling, which consumers may consider an indicator of poor quality. . As a consequence, winemakers often use bentonite, a clay-based material that binds protein, to remove proteins and achieve protein stabilisation. However, removing bentonite from wine after treatment can result in a 3-10% loss of wine (1)…

Optimizing stomatal traits for future climates

Stomatal traits determine grapevine water use, carbon supply, and water stress, which directly impact yield and berry chemistry. Breeding for stomatal traits has the strong potential to improve grapevine performance under future, drier conditions, but the trait values that breeders should target are unknown. We used a functional-structural plant model developed for grapevine (HydroShoot) to determine how stomatal traits impact canopy gas exchange, water potential, and temperature under historical and future conditions in high-quality and hot-climate California wine regions (Napa and the Central Valley). Historical climate (1990-2010) was collected from weather stations and future climate (2079-99) was projected from 4 representative climate models for California, assuming medium- and high-emissions (RCP 4.5 and 8.5). Five trait parameterizations, representing mean and extreme values for the maximum stomatal conductance (gmax) and leaf water potential threshold for stomatal closure (Ψsc), were defined from meta-analyses. Compared to mean trait values, the water-spending extremes (highest gmax or most negative Ysc) had negligible benefits for carbon gain and canopy cooling, but exacerbated vine water use and stress, for both sites and climate scenarios. These traits increased cumulative transpiration by 8 – 17%, changed cumulative carbon gain by -4 – 3%, and reduced minimum water potentials by 10 – 18%. Conversely, the water-saving extremes (lowest gmax or least negative Ψsc) strongly reduced water use and stress, but potentially compromised the carbon supply for ripening. Under RCP 8.5 conditions, these traits reduced transpiration by 22 – 35% and carbon gain by 9 – 16% and increased minimum water potentials by 20 – 28%, compared to mean values. Overall, selecting for more water-saving stomatal traits could improve water-use efficiency and avoid the detrimental effects of highly negative canopy water potentials on yield and quality, but more work is needed to evaluate whether these benefits outweigh the consequences of minor declines in carbon gain for fruit production.

New plant protein extracts as fining agents for red wines

AIM: Quinoa (Chenopodium quinoa) is a non-allergenic pseudocereal with a high protein content