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…

Advancement of grape maturity – comparison between contrasting varieties and regions

Grapevine phenology has advanced across many regions, nationally and internationally, in recent decades under the influence of increasing temperatures, resulting in earlier
vintages (Jones and Davis, 2000, Petrie and Sadras, 2008, Tomasi et al., 2011, Webb et al., 2011. Earlier vintages have several ramifications for the wine industry. There are direct implications on quality, due to the fruit ripening during the hotter conditions of summer and early autumn, which then impacts grape composition and wine style (Sadras et al., 2013, Buttrose et al., 1971, Mira de Ordũna, 2010). There are also indirect implications where the fruit is perceived to ripen at a faster rate and the crop reach optimum maturity over a shorter period (Coulter et al., 2016).

Late frost protection in Champagne

Probably one of the most counterintuitive impacts of climate change on vine is the increased frequency of late frost. Champagne, due to its septentrional position is historically and regularly affected by this meteorological hazard. Champagne has therefore developed a strong experience in frost protection with first experiments dating from the end of 19th century. Frost protection can be divided in two parts: passive and active. Passive protection includes all the methods that do not seek to modify the vine’s environment or resistance at the time of frost. The most iconic passive protection in Champagne is the establishment of the individual reserve. This reserve allows to stock a certain quantity of clear wine during a surplus year to compensate a meteorological hazard like frost during the following years. Other common passive methods are the control of planting area (walls, bushes, topography), the choice of grape variety, late pruning, or the impact of grass cover and tillage. Active frost protection is also divided in two parts. Most of the existing techniques tend to modify vine’s environment. Most of the time they provide warmth (candles, heaters, windmills, heating cables…), or stabilise bud’s temperature above a lethal threshold (water sprinkling). The other way to actively fight is to enhance the resistance of buds to frost (elicitors). The Comité Champagne evaluates frost protection methods following three main axes: the efficiency, the profitability, and the environmental impact through a lifecycle assessment. This study will present the results on both passive and active protection following these three axes.

Do high temperature extremes impact berry tannin composition?

Flavonoids, including flavonols, anthocyanins, and tannins, are important contributors to grape and wine quality, and their biosynthesis is strongly influenced by bunch microclimate.

Evaluation of wood starch content on bench grafting success rate in grapevine

Since the emergence of phylloxera, grafting has been the most used propagation method in viticulture. Despite all the improvement measures implemented in the nurseries, it is frequent that graft success rates vary depending on the nursery process and scion/rootstock combinations. The reasons behind this unsatisfactory behaviour are still unknown and can be diverse, although carbohydrate reserves might be hypothesised to be crucial, since callus, root, and new tissue formation will be built based on them. In order to identify the effect of carbohydrates on grafting success, nine combinations were established based on the starch content in grapevine scionwoods (cv. Tempranillo clone VN69) and rootstocks cuttings (110 Richter clone 237) used for grafting: Low (L), Medium (M), High (H).

Viñedos de la D.O. Ribeira Sacra: heterogeneidad varietal y sanitaria

La D.O. Ribeira Sacra (Galicia, N.O. de España) se distribuye a lo largo de las riberas de los ríos Miño y Sil. Su característica mas destacada son las fuertes pendientes. Desde 1990 se estudia el estado