Search results for "Mildew"

USE OF ALGINATES OLIGOMERS TO IMPROVE PLANT PROTECTION AGAINST PATHOGENS

2021

The invention concerns the use of alginate oligomers in sequence α(1-4)Guluronane and/or ß(1-4)Mannuronane having a DP greater than 30, as an active ingredient of biocontrol products in plants, and that may be combined with another molecules such as phytohormones, against cryptogamic diseases of plants, in particular of vine (Vitis vinifera), or to protect other species against aggressors such as pathogenic microbes or insects.

POLYSACCHARIDE COMPOUNDS AND USE OF SAME FOR STIMULATING DEFENCE RESPONSES OF PLANTS AGAINST PATHOGENIC MICROORGANISMS

2020

The present invention relates to novel oligogalacturonans having a degree of methylation of 0 and a degree of polymerisation of 1 to 10, and to use there of for stimulating defence responses of plants against pathogenic microorganisms.

Climate change impacts on phytosanitary risk evolution in north-eastern France vineyards : observations and modeling : The case of powdery mildew

2021

From now on, agriculture must adapt and anticipate climate change, whose impact has already been observed on the biology of crops and their production. Beyond plants, this climate change also impacts pathogen development and therefore host/pathogen interactions. Thus, building adaptation strategies requires considering not only the crops but also the organisms with which they interact.The objective of this thesis is to characterize the impact of climate change on the phytosanitary risk related to grapevine powdery mildew (Erysiphe necator) in the wine regions of Burgundy and Champagne. More particularly, it questions two central aspects related to the epidemic risk: the grapevine sensitive …

Arbuscular mycorrhizal fungi influence host infection during epidemics in a wild plant pathosystem

2022

SummaryWhile pathogenic and mutualistic microbes are ubiquitous across ecosystems and often co-occur within hosts, how they interact to determine patterns of disease in genetically diverse wild populations is unknown.To test whether microbial mutualists provide protection against pathogens, and whether this varies among host genotypes, we conducted a field experiment in three naturally-occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected epidemiological data on experimental plants from six allopatric populations that had been inoculated with a mixture of mutualistic arb…

An ethoxylated surfactant enhances the penetration of the sulfated laminarin through leaf cuticle and stomata, leading to increased induced resistanc…

2016

International audience; Some β-1,3-glucans and particularly sulfated laminarin (PS3) are known as resistance inducers (RIs) in grapevine against the downy mildew. However, their efficacy in vineyard is still often too low, which might be caused by a limited penetration through the leaf cuticle following spray application. We used (14) C-sucrose uptake experiments with grapevine leaves in order to select a surfactant as saccharide penetration enhancer. Our results showed that though sucrose foliar uptake was low, it was strongly enhanced by Dehscofix CO125 (DE), a highly ethoxylated surfactant. Fluorescent saccharides were then produced and laser scanning microscopy was used to analyze their…

DISEASES DIVERSITY FOR FLAX GENETIC RESOURCES IN LATVIA

2017

Flax ( Linum usitatissimum L) yield of stem and seeds and them quality is influenced by a number of harmful diseases but investigation about pathogens in recent years have not been done in Latvia.  Each stage of development of disease is important in the pathogen life cycle and requires certain condition. Goal of this study have identify possibilities of the pathogens and were assess disease severity depending on the genotypes on flax in variable environmental conditions. The resistance to the diseases for 24 flax genotypes and standard variety ‘Vega 2’ were evaluated. The field trials have been carried out over the period from 2015 to 2016 at the Research Centre of Priekuli, part of Vilani…

Powdery mildew on Rhododendron caused by Erysiphe azaleae in Latvia.

2013

In 2002 a fungus causing powdery mildew on Rhododendron in Latvia was discovered and identified as Erysiphe azaleae. The powdery mildew has since then been observed on leaves and seed pods of deciduous azaleas as well as evergreen rhododendrons, although the disease is more common on taxa of deciduous azaleas. Development of mature chasmothecia has been noticed at every location where the disease was detected. The distribution area of E. azaleae is expanding gradually from the south-west and central regions to the north and east parts of Latvia. It has been suggested, that climate change and large-scale plant import favour this process. To our knowledge, Latvia is so far the farthest north-…

Exploring the factors affecting spatio-temporal variation in grapevine powdery mildew

2019

Chitin Deacetylase, a Novel Target for the Design of Agricultural Fungicides

2021

Fungicide resistance is a serious problem for agriculture. This is particularly apparent in the case of powdery mildew fungi. Therefore, there is an urgent need to develop new agrochemicals. Chitin is a well-known elicitor of plant immunity, and fungal pathogens have evolved strategies to overcome its detection. Among these strategies, chitin deacetylase (CDA) is responsible for modifying immunogenic chitooligomers and hydrolysing the acetamido group in the N-acetylglucosamine units to avoid recognition. In this work, we tested the hypothesis that CDA can be an appropriate target for antifungals using the cucurbit powdery mildew pathogen Podosphaera xanthii. According to our hypothesis, RNA…

A β-1,3 Glucan Sulfate Induces Resistance in Grapevine against Plasmopara viticola Through Priming of Defense Responses, Including HR-like Cell Death

2008

Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybri…