GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Essential oil vapor triggers resistance pathways in Vitis vinifera and blocks plasmopora viticola infection

Essential oil vapor triggers resistance pathways in Vitis vinifera and blocks plasmopora viticola infection

Abstract

The amount of synthetic pesticides applied in viticulture is relatively high compared to other agricultural crops, due to the high sensitivity of grapevine to diseases such as downy mildew (Plasmopora viticola). Alternatives to reduce fungicides are utterly needed to promote a sustainable vineyard-ecosystems and meet consumer acceptance.
Essential oils (EOs) are amongst the most promising natural plant protection agents and have shown their antifungal properties previously. However, the efficiency of EOs depends highly on timing and application technique. Additionally, the molecular interactions of host, pathogen and EO, which underlie the efficiency of EOs, are not understood. The presented study aimed to a) evaluate whether a continuous fumigation of EO can control downy mildew and b) decipher molecular mechanisms triggered in host and pathogen by EO. A custom made climatic chamber was constructed, which enabled a continuous fumigation of vines with different EOs during long term experiments.
Several experiments were carried out with vine cuttings infected with Plasmopora viticola and subsequently exposed to continuous fumigation of different EOs with different concentrations and application times (24 h to 10 d). Experiments were stopped when infection symptoms were clearly present on the control. Physiological parameters (photosynthesis, growth rate) were recorded and leaves were sampled at different time points for subsequent RNA extraction.
The post-infection oregano oil vapor treatment during 24h was sufficient to reduce downy mildew development to 95%. Leaf RNA sampled after 24 hours and 10 days of EO treatment was used for RNA-seq analysis. Sequenced reads were mapped onto the Vitis vinifera and Plasmopora viticola genomes. Less than 1% of reads could be mapped onto the Plasmopora genome from treated samples, whereas up to 30 % reads mapped from the controls, thereby confirming visual observation of P. viticola absence under treatment. An average of 80 % reads could be mapped onto the V. vinifera genome for differential expression analysis, which yielded 4800 modulated transcripts. Grapevine genes triggered by EO treatment were mainly linked to plant biotic stress response and plant-pathogen interactions. Key genes controlling ethylene synthesis, phenylpropanoids and flavonoid synthesis were also highly activated by EO. We report here for the first time the effects of EO treatments on the control of a grapevine pathogen, concomitantly with the molecular description of EO-host-pathogen interactions. These results strongly support the hypothesis that the antifungal efficiency of EO is indirect and mainly due to switching on resistance pathways of the host plants. These results are of major importance for the production and research on biopesticides, plant stimulation products as well as for resistance breeding strategies.

DOI:

Publication date: September 26, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Markus RIENTH1*, Sana GHAFFARI1, Marylin CLÉROUX1, Arnaud PERNET1, Julien CROVADORE3, Eric REMOLIF2 Jean-Philipp BURDET1, Francois LEFORT3

1 Changins, HES-SO University of Applied Sciences and Arts Western Switzerland, route de Duillier 60, 1260 Nyon, Switzerland
2 Agroscope, route de Duillier 50, 1260 Nyon, Switzerland
3 HEPIA, HES-SO University of Applied Sciences and Arts Western Switzerland, Jussy, Switzerland

Contact the author

Keywords

plant defense, essential oil, Plasmopara viticola, grapevine

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Local ancient grapevine cultivars to face future viticulture

Among the different strategies to cope with the negative impacts of climate change on viticulture, the exploitation of genetic diversity is one of the most promising to adapt to new conditions and maintain wine production and quality. One of the biggest concerns in the context of climate change is to improve water use efficiency (WUE). In this way, the use of genotypes that present a better response to drought and high WUE is a key issue. In this work, physiological performance analysis was conducted to compare the water deficit stress (WDS) responses of local and widespread grapevines cultivars. Leaf gas exchange, water use efficiency (WUE) at different levels (leaf and long-term WUE (∆13C)), leaf osmotic adjustment and other water relations parameters were determined in plants under well-watered and WDS conditions alongside assessment of the levels of foliar hormones concentrations. Results denote that local cultivars displayed better physiological performance under WDS as compared to the widely-distributed ones. he results corroborate the hypothesis that better stomatal control allows increasing leaf WUE under drought as occurred in the local Callet cv.; but the minority local cultivar Escursac cv. showed high WUE under both treatments. In this case, high WUE can be related to maintaining higher photosynthetic activity under drought. The different mechanisms underlying the better performance under WDS and high WUE of minority local cultivars are discussed.

Using δ13C and hydroscapes as a tool for discriminating cultivar specific drought response

Measurement of carbon isotope discrimination in berry juice sugars at maturity (δ13C) provides an integrated assessment of water use efficiency (WUE) during the period of berry ripening, and when collected over multiple seasons can be used as an indication of drought stress response. Berry juice δ13C measurements were carried out on 48 different varieties planted in a common garden experiment in Bordeaux, France from 2014 through 2021 and were paired with midday and predawn leaf water potential measurements on the same vines in a subset of six varieties. The aim was to discriminate a large panel of varieties based on their stomatal behaviour and potentially identify hydraulic traits characterizing drought tolerance by comparing δ13C and hydroscapes (the visualisation of plant stomatal behaviour as a response to predawn water potential). Cluster analysis found that δ13C values are likely affected by the differing phenology of each variety, resulting in berry ripening of different varieties taking place under different stress conditions within the same year. We accounted for these phenological differences and found that cluster analysis based on specific δ13C metrics created a classification of varieties that corresponds well to our current empirical understanding of their relative drought tolerances. In addition, we analysed the water potential regulation of the subset of six varieties (using the hydroscape approach) and found that it was well correlated with some δ13C metrics. Surprisingly, a variety’s water potential regulation (specifically its minimum critical leaf water potential under water deficit) was strongly correlated to δ13C values under well-watered conditions, suggesting that base WUE may have a stronger impact on drought tolerance than WUE under water deficit. These results give strong insights on the innate WUE of a very large panel of varieties and suggest that studies of drought tolerance should include traits expressed under non-limiting conditions.

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

A multidisciplinary approach to evaluate the effects of the training system on the performance of “Aglianico del Vulture” vineyards

Vineyards are complex agro-ecosystems with high spatial and temporal variability. An efficient training system may counteract the adverse effects of this variability. Moreover, considering the climate change issues, choosing an efficient training system that enhances water use and protects the vines from radiative thermal stress has become a priority for the farmers. A multidisciplinary approach that assesses the soil-crop-yield-wine relationships of vineyards in a distributed and holistic way could bring added knowledge on the behavior of the different training systems. This ongoing research aimed to implement a multidisciplinary approach to study the behavior of “Aglianico del Vulture” grapevines trained with two different systems: a spurred cordon (SC) and an “Alberello in parete” (AL), grown in a high-quality wine production area of Basilicata region (Italy). The approach merged several methods and scales of soil, ecophysiology, must/wine quality, and spectral data collection to assess the influence of the training system. Homogeneous zones (HZs) in both training systems were defined through a procedure based on geomorphological classification, unmanned aerial vehicles (UAV) images analysis, and a traditional soil survey supported by geophysical scanning. During the 2021 season, TDR probes monitored soil water content, while grapevine health status was assessed using eco-physiological measurements (LWP, chlorophyll content, PSII photosynthetic efficiency, LAI, and point-based field spectroscopy). These grapevine in-vivo measurements validated the spectral vegetation indexes (NDVI, RENDVI, CVI, and TVI) derived from the UAV multispectral imagery, which monitored the grapevine status in a distributed and non-invasive way. Grape yield, quality of berries, must and wine were measured to assess the effects of the training systems. The first experimental year results showed the variability of the vineyards and revealed relationships among soil parameters, crop characteristics, and vegetation indices of the SC and AL training systems. This multidisciplinary study could bring new insights into the vineyard training system’s effects on grape yield and wine quality.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares