terclim by ICS banner
IVES 9 IVES Conference Series 9 Unveiling the Grapevine Red Blotch Virus (GRBV) host-pathogen arms-race via multi-omics for enhanced viral defense 

Unveiling the Grapevine Red Blotch Virus (GRBV) host-pathogen arms-race via multi-omics for enhanced viral defense 

Abstract

The Grapevine Red Blotch Virus (GRBV) poses a critical challenge to the wine sector, lacking a uniquely identified vector. Current control methods involve costly and labor-intensive vine removal, emphasizing the urgency for targeted alternatives. The limited understanding of intricate host-virus interactions underscores the need for foundational knowledge to develop innovative disease control strategies. These include efforts to boost the plant’s RNA interference (RNAi) response, including RNA-based topical applications. Our research investigates the early GRBV infection stages, aiming to unravel the “arms race” between the plant’s RNAi machinery and the viral counter-defense strategies. Following an Agrobacterium tumefaciens-mediated infiltration with an infectious clone containing the GRBV genome, we detected a peak of viral activity in infected microvine plants one-week post-infection. Small RNA sequencing from infected tissues identified 21, 22, and 24 nucleotides virus-derived small-interfering RNAs (vsiRNAs), suggesting post-transcriptional and transcriptional gene silencing activity. We utilized a custom bioinformatics pipeline to identify GRBV “hotspots,” that were further validated as RNAi precursors through secondary structure predictions. GRBV-targeted bisulfite sequencing revealed hypermethylation within GRBV hotspots, establishing a crucial link between small RNA production and effective methylation of the virus, culminating at 24 days post-infection (dpi).

Examining the plant transcriptome and methylome during early infection dates (3, 6, 12 and 24 dpi) unveiled molecular strategies employed by both organisms to counteract each other. The multilayered OMICs data we generated constitute the foundation for innovative viral defense strategies.  This strategy could enhance GRBV management, ensuring sustainable vineyard practices by integrating molecular biology insights into agriculture.

DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Article

Authors

Christian Mandelli1*, Laurent G. Deluc1,2

1 Department of Horticulture, Oregon State University, Corvallis, OR, United States
2 Oregon Wine Research Institute, Oregon State University, Corvallis, OR, United States

Contact the author*

Keywords

Grapevine Red Blotch Virus (GRBV), Host-virus interactions, small RNA-seq, genome-wide OMICs

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Regulation of terpene production in methyl jasmonate treated cell-cultures

Terpenes are responsible for flavors and aromas of grapes, however, they also protect from radiation, participate in biotic stress and antioxidant mechanisms. The phytohormone methyl jasmonate (MeJA) mediates many of these stress responses and has been associated with increased terpene content in berries. Here, we generated transcriptomic data of Vitis vinifera cv. ‘Gamay’ cells treated with MeJA (100 μM) and cyclodextrins (50 μM) to understand these responses. Ontology analysis revealed that up-regulated genes (URGs) were enriched in jasmonic acid biosynthesis and signaling terms, as expected. Inspection of transcription factors (TFs) among URGs allowed us to study uncharacterized TFs.

Aromas of Riesling wine: impact of bottling and storage conditions

Storage temperature and bottling parameters are among the most important factors, which influence the development of wine after bottling. It is well studied that higher storage temperatures speed up chemical reactions and results in faster wine aging [1,2]. It is also known that higher SO2 level and lower oxygen content provide better protection and longer shelf-life for the wine. At the same time, the mechanisms of chemical transformations of wine aromas during the aging process are not fully understood. In particular, how oxidation reactions contribute to the transformations of varietal aroma compounds.In the present study [3], we investigated the development of Riesling wine depending on a series of bottling conditions, which differed in the free SO2 level in wine (low—13 mg/L, medium—24 mg/L, high—36 mg/L), CO2 treatment of the headspace.

Bioprotection en phase pré-fermentaire, synthèse de 3 ans d’expérimentations dans différentes régions viticoles

With growing consumer interest in products without chemical additives, limiting the use of sulfites is a priority for the wine industry. Bioprotection is a biological alternative that avoids or reduces the risks of alterations that have a negative impact on the organoleptic quality of wines and, ultimately, on their acceptability to consumers. bioprotection can also provide a response to the risks of microbiological deviations, which are increased both by climate change and by the organization of harvesting operations, which increasingly include the use of multi-bins filled at the vine, exposing the harvest to sometimes high temperatures for longer periods of time.

Functionality of different inter-stimulus rinse protocols for the sensory analysis of wildfire affected wines

From the effect of global climate change, wildfire occurrence during grape ripening has increased. These wildfires produce smoke that can carry organic compounds to a vineyard. These smoke compounds are adsorbed in the grape berry and result in wines with elevated levels of smoke-related phenols. These wines are described as having a smokey, burnt, and dirty aroma (Kristic et al, 2015). Not only are volatile phenols carried by smoke, but additionally glycoconjugate forms of these phenols are present as will. These have been found to have a large impact on the flavor of wines, being the cause of a lasting ashy aftertaste post consumption (Parker et al, 2012). When evaluating the sensory profile of these wines when tasted one after the other, there is an observed problem due to the lasting nature of these undesirable attributes and high level of carry-over from sample to sample. The aim of this work is to evaluate the extent this carryover occurs, along with the best sensory practices to mitigate its influence via different inter-stimulus rinse protocols.

May lactic acid bacteria play an important role in sparkling wine elaboration?

The elaboration of sparkling wine is a demanding process requiring technical as well as scientific skills. Uncovering the role of the terroir to the final product quality is of great importance for the wine market. Although the impact of the yeast strains and their metabolites on the final product quality is well documented, the action of bacteria still remains unknown. The malolactic fermentation (MLF) is carried out by the lactic acid bacteria after the alcoholic fermentation in order to ensure the microbial stability during the second fermentation that takes place in the bottle or in tanks. Oenococcus oeni is the only selected species to drive MLF that has been commercialized for sparkling wine elaboration and it is naturally present on grapes, in the cellar and also in the final product. However, whether the bacterial strain contributes to the sensory characteristics of sparkling wine is still questioned.