GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Impact of grapevine leafroll virus infections on vine physiology and the berry transcriptome

Impact of grapevine leafroll virus infections on vine physiology and the berry transcriptome

Abstract

Context and purpose of the study ‐ Grapevine leafroll associated virus (GLRaV) infections deteriorate vine physiological performance and cause high losses of yield and fruit quality and are thus causing serious economic losses in the wine industry. Physiological and molecular studies on the impact of leafroll infections on plant and fruit metabolism are relatively scare and the molecular mechanisms associated with the plant response to the virus during berry ripening are not well understood so far. Commonly observed phenotypic alterations consist in a ripening delay, a reduction in anthocyanin and sugar accumulation. The few molecular studies associated in particular the lack of anthocyanin of berries of infected vines to a repression of key genes of anthocyanin biosynthesis. However such studies did never account for berry heterogeneity and potential phenological shifts induced by virus infection, which could have introduced biases in gene expression studies.

Material and methods ‐ In the present study a long‐term experiment was established in the year 2000, with the aim to investigate the effects of infections with different GLRaVs (GLRaV 1 & GLRaV 1+3) on vine and grape physiology. Physiological data (yield, vigor, photosynthesis, berry quality) has been collected from 2015 to 2018. In 2018 a transcriptomic (RNA‐seq) analysis of 2 reconstituted berry ripening stages was performed. Therefore 245 berries were individually sampled and individually analyzed for sugar and organic acids in order to re‐constitute 2 homogenous ripening stages to circumvent intercluster berry heterogeneity and thus to compensate for phenological shifts induced by virus infections. RNA of reconstituted samples was extracted and sequenced by single end sequencing and subsequently analyzed for differentially expressed genes (DEGs).

Results ‐ Physiological measurement showed a significant decrease in photosynthesis, yield and sugar content, which were highly significant in the co‐infected vines (GLRaV 1+3). RNA‐sequencing of berries revealed a total of 2136 DEGs between control and virus infections. Several transcriptions factors related to abiotic and biotic stress could be identified and showed interesting variation in dependence to ripening stage and infection severity. Strikingly previously reported repression of the anthocyanin biosynthesis and sugar metabolism could not be confirmed by gene expression. This illustrates that the main damaging effect on GLRaV infection is rather related to a phenological shift than to a direct impact on metabolism. The here reported results give new insight in the mechanism of leafroll infection and emphasize the importance of the sampling protocol of molecular studies investigating berry metabolism. 

DOI:

Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article

Authors

Markus RIENTH (1), Sana GHAFFARI (1,2), Jean‐Sébastien REYNARD (3)

(1) Changins, haute ecole de viticulture et œnologie, route de Duillier 50, 1260 Nyon, Switzerland
(2) Higher Institute of Applied Biology of Medenine, Route el Djorf km 22.5, 4119 Medenine, Tunisia
(3) Agroscope, route de Duillier 50, 1260 Nyon, Switzerland

Contact the author

Keywords

Grapevine leafroll virus, GLRaV 1, GLRaV 3, RNA‐seq, berry metabolism

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Olfactometric and sensory study of red wines subjected to ultrasound or microwaves during their elaboration

The effect that some extraction techniques, such as ultrasound (Cacciola, Batllò, Ferraretto, Vincenzi, & Celotti, 2013; Povey & McClements, 1988) or microwaves (Carew, Close, & Dambergs, 2015; Carew, Gill, Close, & Dambergs, 2014) produce on the aroma of red wines, when applied to processes of extractive nature, such as pre-fermentative maceration or ageing with oak chips (Spanish oak – Quercus pyrenaica and French oak – Quercus robur) has been studied. The volatile profile was determined by means of gas chromatography coupled with olfactometric and mass spectrometric detection. A sensory analysis was also carried out. No indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines whereas the application of such energies during the ageing phase showed some positive trends at sensory level.

Methodology of climate modelling using land surface temperature downscaling: case study case of Gironde (France)

Aim: Climate modelling in viticulture introduced new challenges such as high spatio-temporal monitoring and the use of dependable time series and robustness modelling methods. Land surface temperature (LST) is widely used and particularly MODIS thermal satellite images due to their high temporal resolution (four images per day).

The moment of preharvest elicitor application influence its final effect on winegrapes quality

Phenolic compounds are secondary metabolites of grapes. Plants produce a wide variety of this type of metabolites through diverse biosynthesis pathways and their production is sometimes a response to external stimuli, either environmental or biotic stresses. Some of them may act as chemical defenses against pathogens or herbivores and their synthesis is increased when the attack exists. However, it is remarkable that the synthesis of these interesting compounds can be activated even when the stimulus is not present, with the use of elicitors. These are substances that when applied exogenously trigger the biosynthetic pathways conducting to the synthesis of these defense compounds.

Cover crop management and termination timing have different effects on the maturation and water potentials of Glera (Vitis vinifera L.) in Friuli-Venezia Giulia

Inter-row soil tillage in vineyards, stimulates vigor and production due to the absence of competition for water and nutrients, however negatively affects organic matter content, soil erosion, and compaction, resulting in reduced fertility. In this study, we investigated the effects of different cover crop management approaches, including cultivation type and termination timing, on the physiological and productive responses of a Glera vineyard.
The experimental trial was conducted in Precenicco (UD) from 2019 to 2021. A commercial mixture for autumn cover cropping was sown in alternating rows, and the sowing pattern was changed each year.

NEW INSIGHTS INTO THE FATE OF MARKERS INVOLVED IN FRESH MUSHROOM OFF-FLAVOURS DURING ALCOHOLIC FERMENTATION

The fresh mushroom off-flavour (FMOff) has been appearing in wines since the 2000s. Some C8 compounds such as 1-octen-3-one, 1-octen-3-ol, 1-hydroxyoctan-3-one, 3-octanol and others are involved in this specific off-flavour [1-3]. At the same time, glycosidic precursors of some FMOff compounds have been identified in musts contaminated by Crustomyces subabruptus [4], highlighting the role of aroma precursors in this specific taint. However, the fate of these volatile molecules and glycosidic fractions during fermentation is not well known.