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1.
Front Plant Sci ; 15: 1394821, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38716339

RESUMO

Botryosphaeria dieback is a grapevine trunk disease caused by fungi of the Botryosphaeriaceae family, which attacks more specifically the woody tissues. The infection leads to different symptoms including a severe form with a leaf drop as well as premature plant death. Botryosphaeria dieback causes major economic losses, since no effective treatment is yet available. A better understanding is necessary to find solutions to fight this disease. In this study, our objective was to characterize the "leaf drop" form by (1) looking for the presence of pathogens in the basal internodes of stems, (2) quantifying blocked vessels by tylosis and/or gummosis, and (3) describing the impact of the disease on vine physiology (gene expression and metabolome) and development (establishment and functioning of the cambium and phellogen) at the level of xylem and phloem of basal stem internodes. Our study has shown that Botryosphaeriaceae were present in both phloem and xylem of the basal internodes of the annual stem, with xylem vessels obturated. We have also clearly demonstrated that gene expression and metabolite profiles were strongly modified in both xylem and phloem of diseased plants. Differences in stems between healthy (control, C) and diseased (D) plants were low at flowering (vines not yet symptomatic), higher at the onset of symptom expression and still present, although less marked, at full disease expression. qRT-PCR analysis showed in both phloem and xylem an overexpression of genes involved in plant defense, and a repression of genes related to meristematic activity (i.e. vascular cambium and phellogen). Metabolomic analysis showed specific fingerprints in stems of healthy and diseased plants from the onset of symptom expression, with an increase of the level of phytoalexins and mannitol, and a decrease of 1-kestose one. At the structural level, many alterations were observed in internodes, even before the onset of symptoms: a classical obstruction of xylem vessels and, for the first time, a disorganization of the secondary phloem with an obstruction of the sieve plates by callose. The disease modifies the development of both secondary phloem (liber) and phellogen. Altogether, this study combining different approaches allowed to highlight deep vine dysfunction in the internodes at the base of stems, that may explain vine decline due to Botryosphaeria dieback.

2.
Food Res Int ; 173(Pt 2): 113383, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803722

RESUMO

The reduction of chemical inputs in wine has become one of the main challenges of the wine industry. One of the alternatives to sulfites developed is bioprotection, which consists in using non-Saccharomyces strains to prevent microbial deviation. However, the impact of substituting sulfites by bioprotection on the final wine remains poorly studied. For the first time, we characterized this impact on Chardonnay wine through an integrative approach. Interestingly, physico-chemical analysis did not reveal any difference between both treatments regarding classical oenological parameters. Nevertheless, bioprotection did not seem to provide as much protection against oxidation as sulfites, as observed through phenolic compound analysis. At a deeper level, untargeted metabolomic analyses revealed substantial changes in wine composition according to must treatment. In particular, the specific footprint of each treatment revealed an impact on nitrogen-containing compounds. This observation could be related to modifications in S. cerevisiae metabolism, in particular amino acid biosynthesis and tryptophan metabolism pathways. Thus, the type of must treatment seemed to impact metabolic fluxes of yeast differently, leading to the production of different compounds. For example, we observed glutathione and melatonin, compounds with antioxidant properties, which were enhanced with sulfites, but not with bioprotection. However, despite substantial modifications in wines regarding their chemical composition, the change in must treatment did not seem to impact the sensory profile of wine. This integrative approach has provided relevant new insights on the impact of sulfite substitution by bioprotection on Chardonnay wines.


Assuntos
Sulfitos , Vinho , Saccharomyces cerevisiae , Fermentação , Vinho/análise , Metabolômica
3.
Front Plant Sci ; 14: 1141700, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37180397

RESUMO

In the past, most grapevine trunk diseases (GTDs) have been controlled by treatments with sodium arsenite. For obvious reasons, sodium arsenite was banned in vineyards, and consequently, the management of GTDs is difficult due to the lack of methods with similar effectiveness. Sodium arsenite is known to have a fungicide effect and to affect the leaf physiology, but its effect on the woody tissues where the GTD pathogens are present is still poorly understood. This study thus focuses on the effect of sodium arsenite in woody tissues, particularly in the interaction area between asymptomatic wood and necrotic wood resulting from the GTD pathogens' activities. Metabolomics was used to obtain a metabolite fingerprint of sodium arsenite treatment and microscopy to visualize its effects at the histo-cytological level. The main results are that sodium arsenite impacts both metabolome and structural barriers in plant wood. We reported a stimulator effect on plant secondary metabolites in the wood, which add to its fungicide effect. Moreover, the pattern of some phytotoxins is affected, suggesting the possible effect of sodium arsenite in the pathogen metabolism and/or plant detoxification process. This study brings new elements to understanding the mode of action of sodium arsenite, which is useful in developing sustainable and eco-friendly strategies to better manage GTDs.

4.
Plants (Basel) ; 12(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36840101

RESUMO

(1) Background: Grapevine trunk diseases (GTDs) have become a global threat to vineyards worldwide. These diseases share three main common features. First, they are caused by multiple pathogenic micro-organisms. Second, these pathogens often maintain a long latent phase, which makes any research in pathology and symptomatology challenging. Third, a consensus is raising to pinpoint combined abiotic stresses as a key factor contributing to disease symptom expression. (2) Methods: We analyzed the impact of combined abiotic stresses in grapevine cuttings artificially infected by two fungi involved in Botryosphaeria dieback (one of the major GTDs), Neofusicoccum parvum and Diplodia seriata. Fungal-infected and control plants were subjected to single or combined abiotic stresses (heat stress, drought stress or both). Disease intensity was monitored thanks to the measurement of necrosis area size. (3) Results and conclusions: Overall, our results suggest that combined stresses might have a stronger impact on disease intensity upon infection by the less virulent pathogen Diplodia seriata. This conclusion is discussed through the impact on plant physiology using metabolomic and transcriptomic analyses of leaves sampled for the different conditions.

5.
Front Plant Sci ; 13: 998273, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36438082

RESUMO

Using plant defense elicitors to protect crops against diseases is an attractive strategy to reduce chemical pesticide use. However, development of elicitors remains limited because of variable effectiveness in the field. In contrast to fungicides that directly target pathogens, elicitors activate plant immunity, which depends on plant physiological status. Other products, the biostimulants, can improve certain functions of plants. In this study, the objective was to determine whether a biostimulant via effects on grapevine physiology could increase effectiveness of a defense elicitor. A new methodology was developed to study biostimulant activity under controlled conditions using in vitro plantlets. Both biostimulant and defense elicitor used in the study were plant extracts. When added to the culture medium, the biostimulant accelerated the beginning of plantlet growth and affected the shoot and root development. It also modified metabolomes and phytohormone contents of leaves, stems, and roots. When applied on shoots, the defense elicitor changed metabolite and phytohormone contents, but effects were different depending on whether plantlets were biostimulated or controls. Defense responses and protection against Plasmopara viticola (downy mildew agent) were induced only for plantlets previously treated with the biostimulant, Therefore, the biostimulant may act by priming the defense elicitor action. In this study, a new method to screen biostimulants active on grapevine vegetative growth was used to demonstrate that a biostimulant can optimize the efficiency of a plant defense elicitor.

6.
Molecules ; 27(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36144763

RESUMO

The present study is aimed at determining whether leaf volatile organic compounds (VOCs) are good markers of the grapevine response to defence elicitors in the field. It was carried out in two distinct French vineyards (Burgundy and Bordeaux) over 3 years. The commercial elicitor Bastid® (Syngenta, Saint-Sauveur, France) (COS-OGA) was first used to optimise the VOCs' capture in the field; by bagging stems together with a stir bar sorptive extraction (SBSE) sensor. Three elicitors (Bastid®, copper sulphate and methyl jasmonate) were assessed at three phenological stages of the grapevines by monitoring stilbene phytoalexins and VOCs. Stilbene production was low and variable between treatments and phenological stages. VOCs-particularly terpenes-were induced by all elicitors. However, the response profiles depended on the type of elicitor, the phenological stage and the vineyard, and no sole common VOC was found. The levels of VOC emissions discriminated between weak (Bastid® and copper sulphate) and strong (methyl jasmonate) inducers. Ocimene isomers were constitutively present in the overall blends of the vineyards and increased by the elicitors' treatments, whilst other VOCs were newly released throughout the growing seasons. Nonetheless, the plant development and climate factors undoubtedly influenced the release and profiles of the leaf VOCs.


Assuntos
Estilbenos , Compostos Orgânicos Voláteis , Acetatos , Sulfato de Cobre , Ciclopentanos , Fazendas , Oxilipinas , Folhas de Planta , Terpenos
7.
J Fungi (Basel) ; 8(2)2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35205905

RESUMO

Copper-based preparations have been used for more than 100 years in viticulture to control downy mildew caused by Plasmopara viticola. LC2017, and a new low-copper-based formulation, has been developed to control grapevine trunk diseases (GTDs). Previous greenhouse studies showed the potential of LC2017 to control GTDs by both fungistatic and plant defense elicitor effects. Here, we further characterize the effects of LC2017 in the field determining its impact on: (i) incidence of Esca, (ii) the vine microbiome, (iii) the vine physiology and (iv) enological parameters of juices. We observed a progressive decrease of cumulate Esca incidence in treated vines over the years with annual fluctuation related to the known erratic emergence of GTD symptoms. Neither harmful effects of LC2017 on the vine microbiota, nor on vine physiology were observed (at both transcriptomic and metabolomic levels). Similarly, no impact of LC2017 was observed on the enological properties of berries except for sugar content in juice from esca-diseased vines. The most important result concerns the transcriptomic profiles: that of diseased and LC2017 treated vines differs from that of disease untreated ones, showing a treatment effect. Moreover, the transcriptomic profile of diseased and LC2017-treated vines is similar to that of untreated asymptomatic vines, suggesting control of the disease.

8.
Front Plant Sci ; 12: 638688, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34267767

RESUMO

The root system plays an essential role in the development and physiology of the plant, as well as in its response to various stresses. However, it is often insufficiently studied, mainly because it is difficult to visualize. For grapevine, a plant of major economic interest, there is a growing need to study the root system, in particular to assess its resistance to biotic and abiotic stresses, understand the decline that may affect it, and identify new ecofriendly production systems. In this context, we have evaluated and compared three distinct growing methods (hydroponics, plane, and cylindric rhizotrons) in order to describe relevant architectural root traits of grapevine cuttings (mode of grapevine propagation), and also two 2D- (hydroponics and rhizotron) and one 3D- (neutron tomography) imaging techniques for visualization and quantification of roots. We observed that hydroponics tubes are a system easy to implement but do not allow the direct quantification of root traits over time, conversely to 2D imaging in rhizotron. We demonstrated that neutron tomography is relevant to quantify the root volume. We have also produced a new automated analysis method of digital photographs, adapted for identifying adventitious roots as a feature of root architecture in rhizotrons. This method integrates image segmentation, skeletonization, detection of adventitious root skeleton, and adventitious root reconstruction. Although this study was targeted to grapevine, most of the results obtained could be extended to other plants propagated by cuttings. Image analysis methods could also be adapted to characterization of the root system from seedlings.

9.
Molecules ; 26(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299533

RESUMO

Grapevine is susceptible to fungal diseases generally controlled by numerous chemical fungicides. Elicitors of plant defence are a way of reducing the use of these chemicals, but still provide inconsistent efficiency. Easy-to-analyse markers of grapevine responses to elicitors are needed to determine the best conditions for their efficiency and position them in protection strategies. We previously reported that the elicitor sulphated laminarin induced the emission of volatile organic compounds (VOCs) by grapevine leaves. The present study was conducted to characterise and compare VOC emissions in response to other elicitors. Bastid® was first used to test the conditions of VOC collection and analysis. Using SBSE-GC-MS, we detected several VOCs, including the sesquiterpene α-farnesene, in a time-dependent manner. This was correlated with the induction of farnesene synthase gene expression, in parallel with stilbene synthesis (another defence response), and associated to resistance against downy mildew. The other elicitors (Redeli®, Romeo®, Bion®, chitosan, and an oligogalacturonide) induced VOC emission, but with qualitative and quantitative differences. VOC emission thus constitutes a response of grapevine to elicitors of various chemical structures. Therefore, VOC analysis is relevant for studying the impact of environmental factors on grapevine defence responses and optimising the performance of elicitors in vineyards.


Assuntos
Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Vitis/microbiologia , Compostos Orgânicos Voláteis/análise , Fungicidas Industriais/análise , Cromatografia Gasosa-Espectrometria de Massas , Folhas de Planta/química , Sesquiterpenos/análise , Vitis/química
10.
Plant Physiol Biochem ; 163: 119-127, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33836466

RESUMO

Acibenzolar acid, the first metabolite formed in planta from the defence inducer acibenzolar-S-methyl (ASM), has been shown to be an inhibitor of the enzyme shikimate hydroxycinnamoyltransferase (HST), extracted from grapevine or tobacco cell suspension cultures. Using a purified recombinant Arabidopsis thaliana HST, the inhibition was found to be competitive, acibenzolar acid binding reversibly to the shikimate binding site of the HST:p-coumaroyl-CoA complex, with a Ki value of 250 µM. The other hydroxycinnamoyltransferases tested in the course of this study, using either hydroxypalmitic acid, putrescine, tyramine, or quinic acid as acyl acceptors were not, or only slightly, inhibited by acibenzolar acid. To understand the specificity of the interaction of acibenzolar acid with HST, we analyzed the structure-activity relationship of a series of benzoic or acibenzolar acid analogues, tested either as AtHST substrates or as inhibitors. This analysis confirmed previously published data on the substrate flexibility of HST and demonstrated that both the carboxyl group and the thiadiazole moiety of acibenzolar acid are playing an important role in the interaction with the shikimate binding site. Acibenzolar acid, which cannot form an ester bond with p-coumaric acid, was however a less potent inhibitor than protocatechuic or 3-hydroxybenzoic acids, which are used as acyl acceptors by HST. Our results show that the interaction of acibenzolar acid with HST, which is probably directly linked to the substrate promiscuity of HST, is unlikely to play a direct role in the defence-inducing properties of ASM in plants.


Assuntos
Ácido Chiquímico , Tiadiazóis , Ácido Quínico , Nicotiana
11.
Physiol Plant ; 171(3): 424-434, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33140863

RESUMO

Esca is a complex grapevine trunk disease caused by wood-rotting ascomycetes and basidiomycetes and leading to several foliar and wood symptoms. Given that the esca expression can be influenced by several environmental, physiological, and genetic factors, foliar symptoms are inconsistent in incidence and prevalence and may appear 1 year but not the following. We have previously reported a clone-dependent expression of the disease in cv Chardonnay. Owing to metabolome analysis, we could discriminate the metabolite fingerprint of green leaves collected on diseased vines of clones 76 and 95. These clone-dependent fingerprints were year-dependent in intensity and nature. The present work was conducted to determine if the clone-dependent disease expression observed is specific to Chardonnay or if it also occurs in another cultivar. A plot located in the Jura vineyard (France) and planted with both 1004 and 1026 clones of Trousseau, a cultivar highly susceptible to esca, was thus selected and studied during 2017 and 2018. A year-dependent variation of the symptoms expression was first observed and a possible relationship with rainfall is hypothesized and discussed. Moreover, a higher percentage of the clone 1026 vines expressed disease, compared to the 1004 ones, suggesting the higher susceptibility of this clone. Finally, metabolomic analyses of the remaining green leaves (i.e, without symptom expression) of partial esca-apoplectic vines allowed us to confirm a clone-dependent metabolic response to the disease. The metabolite fingerprints obtained differed in nature and intensity to those previously reported for Chardonnay and also between years.


Assuntos
Vitis , Células Clonais , Metaboloma , Doenças das Plantas , Folhas de Planta/genética , Vitis/genética
12.
Phytopathology ; 110(11): 1821-1837, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32597304

RESUMO

Botryosphaeria dieback is one of the most significant grapevine trunk diseases that affects the sustainability of the vineyards and provokes economic losses. The causal agents, Botryosphaeriaceae species, live in and colonize the wood of the perennial organs causing wood necrosis. Diseased vines show foliar symptoms, chlorosis, or apoplexy, associated to a characteristic brown stripe under the bark. According to the susceptibility of the cultivars, specific proteins such as PR-proteins and other defense-related proteins are accumulated in the brown stripe compared with the healthy woody tissues. In this study, we enhanced the characterization of the brown stripe and the healthy wood by obtaining a metabolite profiling for the three cultivars Chardonnay, Gewurztraminer, and Mourvèdre to deeper understand the interaction between the Botryosphaeria dieback pathogens and grapevine. The study confirmed a specific pattern according to the cultivar and revealed significant differences between the brown stripe and the healthy wood, especially for phytochemical and lipid compounds. This is the first time that such chemical discrimination was made and that lipids were so remarkably highlighted in the interaction of Botryosphaeriaceae species and grapevine. Their role in the disease development is discussed.


Assuntos
Ascomicetos , Vitis , Metabolômica , Doenças das Plantas , Madeira
13.
Front Plant Sci ; 10: 1117, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31620151

RESUMO

In a context of a sustainable viticulture, the implementation of innovative eco-friendly strategies, such as elicitor-triggered immunity, requires a deep knowledge of the molecular mechanisms underlying grapevine defense activation, from pathogen perception to resistance induction. During plant-pathogen interaction, the first step of plant defense activation is ensured by the recognition of microbe-associated molecular patterns, which are elicitors directly derived from pathogenic or beneficial microbes. Vitis vinifera, like other plants, can perceive elicitors of different nature, including proteins, amphiphilic glycolipid, and lipopeptide molecules as well as polysaccharides, thanks to their cognate pattern recognition receptors, the discovery of which recently began in this plant species. Furthermore, damage-associated molecular patterns are another class of elicitors perceived by V. vinifera as an invader's hallmark. They are mainly polysaccharides derived from the plant cell wall and are generally released through the activity of cell wall-degrading enzymes secreted by microbes. Elicitor perception and subsequent activation of grapevine immunity end in some cases in efficient grapevine resistance against pathogens. Using complementary approaches, several molecular markers have been identified as hallmarks of this induced resistance stage. This review thus focuses on the recognition of elicitors by Vitis vinifera describing the molecular mechanisms triggered from the elicitor perception to the activation of immune responses. Finally, we discuss the fact that the link between elicitation and induced resistance is not so obvious and that the formulation of resistance inducers remains a key step before their application in vineyards.

14.
Carbohydr Polym ; 225: 115224, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521294

RESUMO

Laminaran, a ß-(1→3)-glucan extracted from Laminaria digitata, is a known elicitor of plant defenses, but provides only low level of disease control in vineyard trials. In this context, laminaran was partly hydrophobized by grafting from 1.6 to 7.6 lauryl chains to the native saccharidic chain and the impact of sulfation of the hydrophobized glucans was studied. The activity of the different synthetized laminaran derivatives as antimicrobial agents against Plasmopara viticola, the causal agent of grape downy mildew, and as elicitors of defense reactions in planta, was evaluated. Our results showed that acylation imparts an antimicrobial activity to laminaran which is related to the degree of acylation, AL3, with 7.6 lauryl chains, being the most effective derivative. Sulfation of the acylated laminarans did not further increase the antimicrobial activity. Our results also demonstrated that the efficacy of AL3 against Plasmopara viticola was most likely due to the direct antimicrobial activity of the lauryl chains rather than to an elicitation of plant defenses.


Assuntos
Resistência à Doença , Glucanos/farmacologia , Oomicetos/metabolismo , Doenças das Plantas/microbiologia , Vitis , Anti-Infecciosos/farmacologia , Laminaria/metabolismo , Vitis/metabolismo , Vitis/microbiologia
15.
Mol Plant Pathol ; 20(8): 1037-1050, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31104350

RESUMO

Bacillus subtilis GLB191 (hereafter GLB191) is an efficient biological control agent against the biotrophic oomycete Plasmopara viticola, the causal agent of grapevine downy mildew. In this study, we show that GLB191 supernatant is also highly active against downy mildew and that the activity results from both direct effect against the pathogen and stimulation of the plant defences (induction of defence gene expression and callose production). High-performance thin-layer chromatography analysis revealed the presence of the cyclic lipopeptides fengycin and surfactin in the supernatant. Mutants affected in the production of fengycin and/or surfactin were thus obtained and allowed us to show that both surfactin and fengycin contribute to the double activity of GLB191 supernatant against downy mildew. Altogether, this study suggests that GLB191 supernatant could be used as a new biocontrol product against grapevine downy mildew.


Assuntos
Bacillus subtilis/fisiologia , Lipopeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Doenças das Plantas/microbiologia , Vitis/imunologia , Vitis/microbiologia , Bacillus subtilis/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucanos/biossíntese , Peronospora/efeitos dos fármacos , Peronospora/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Vitis/efeitos dos fármacos , Vitis/genética
16.
J Agric Food Chem ; 67(19): 5512-5520, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31008600

RESUMO

Crude extracts of Vitis vinifera canes represent a natural source of stilbene compounds with well characterized antifungals properties. In our trials, exogenous application of a stilbene extract (SE) obtained from grape canes on grapevine leaves reduces the necrotic lesions caused by Botrytis cinerea. The SE showed to possess a direct antifungal activity by inhibiting the mycelium growth. The activation of some grapevine defense mechanism was also investigated. H2O2 production and activation of mitogen-activated protein kinase (MAPK) phosphorylation cascades as well as accumulation of stilbenoid phytoalexins were explored on grapevine cell suspension. Moreover, the transcription of genes encoding for proteins affecting defense responses was analyzed on grapevine plants. The SE induced some grapevine defense mechanisms including MAPK activation, and the expression of pathogenesis-related (PR) genes and of a gene encoding the glutathione-S-transferase 1 ( GST1) . By contrast, treatment of grapevine leaves with SE negatively regulates de novo stilbene production.


Assuntos
Botrytis/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Extratos Vegetais/farmacologia , Caules de Planta/química , Vitis/química , Vitis/microbiologia , Botrytis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estilbenos/farmacologia
17.
Plant Biotechnol J ; 17(4): 812-825, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30256508

RESUMO

Chitin, a major component of fungal cell walls, is a well-known pathogen-associated molecular pattern (PAMP) that triggers defense responses in several mammal and plant species. Here, we show that two chitooligosaccharides, chitin and chitosan, act as PAMPs in grapevine (Vitis vinifera) as they elicit immune signalling events, defense gene expression and resistance against fungal diseases. To identify their cognate receptors, the grapevine family of LysM receptor kinases (LysM-RKs) was annotated and their gene expression profiles were characterized. Phylogenetic analysis clearly distinguished three V. vinifera LysM-RKs (VvLYKs) located in the same clade as the Arabidopsis CHITIN ELICITOR RECEPTOR KINASE1 (AtCERK1), which mediates chitin-induced immune responses. The Arabidopsis mutant Atcerk1, impaired in chitin perception, was transformed with these three putative orthologous genes encoding VvLYK1-1, -2, or -3 to determine if they would complement the loss of AtCERK1 function. Our results provide evidence that VvLYK1-1 and VvLYK1-2, but not VvLYK1-3, functionally complement the Atcerk1 mutant by restoring chitooligosaccharide-induced MAPK activation and immune gene expression. Moreover, expression of VvLYK1-1 in Atcerk1 restored penetration resistance to the non-adapted grapevine powdery mildew (Erysiphe necator). On the whole, our results indicate that the grapevine VvLYK1-1 and VvLYK1-2 participate in chitin- and chitosan-triggered immunity and that VvLYK1-1 plays an important role in basal resistance against E. necator.


Assuntos
Proteínas de Arabidopsis/metabolismo , Ascomicetos/fisiologia , Quitina/análogos & derivados , Doenças das Plantas/imunologia , Imunidade Vegetal/genética , Proteínas Serina-Treonina Quinases/metabolismo , Vitis/enzimologia , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/imunologia , Proteínas de Arabidopsis/genética , Quitina/metabolismo , Quitina/farmacologia , Quitosana , Oligossacarídeos , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Vitis/genética , Vitis/imunologia
18.
Plant Physiol Biochem ; 133: 134-141, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30408676

RESUMO

Elicitor-induced resistance against diseases is an attractive strategy that could contribute to reduce the use of fungicides for plant protection. However, activation of defenses has an energetic cost that plants have to fuel by a mobilization of their primary metabolism with possible adverse effect on their physiology. In this context, this study was performed to determine whether elicitor-induced resistance of grapevine leaves against downy mildew impacted its development and metabolism. The elicitor PS3 (sulfated ß-glucan laminarin) was sprayed on grapevine herbaceous cuttings grown in greenhouses once or three times, and its impact was studied on young and older grapevine leaves, prior to, and after Plasmopara viticola inoculation. PS3 did not affect grapevine development during the time course of the experiment. A metabolomic analysis, mainly focused on primary metabolites, highlighted a leaf age dependent effect of PS3 treatment. Nitrogen compounds, and sugars to a lesser extent, were impacted. The results obtained complete the current knowledge of the impact of elicitor-induced resistance on plant physiology. They will be helpful to guide further experiments required to better determine the costs and benefits of elicitor-induced resistance in plants.


Assuntos
Resistência à Doença/efeitos dos fármacos , Glucanos/farmacologia , Oomicetos/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Folhas de Planta , Vitis , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Vitis/metabolismo , Vitis/microbiologia
19.
Front Plant Sci ; 9: 1085, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30090107

RESUMO

Protecting vineyards from cryptogamic diseases such as downy mildew, caused by Plasmopara viticola, generally requires a massive use of phytochemicals. However, the issues on unintentional secondary effects on environment and human health, and the occurrence of P. viticola resistant strains, are leading to the development of alternative strategies, such as the use of biocontrol products. In this paper, we evidenced the ability of a plant extract to protect grapevine from P. viticola. Further experiments carried out both on cell suspensions and on plants revealed that plant extract activates typical defense-related responses such as the production of H2O2, the up-regulation of genes encoding pathogenesis-related proteins and stilbene synthase, as well as the accumulation of resveratrol or its derivative piceid. We also brought to light a strong direct effect of PE on the release and motility of P. viticola zoospores. Furthermore, we found out that PE application left dried residues on leaf surface, impairing zoospores to reach stomata. Altogether, our results highlight the different modes of action of a new biocontrol product able to protect grapevine against downy mildew.

20.
Plant Physiol Biochem ; 123: 141-148, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29241147

RESUMO

Elicitors trigger plant defense responses, including phytoalexin production and cell-wall reinforcement. Primary metabolism plays an important role in these responses as it fuels the associated energetic costs and provides precursors for the synthesis of the numerous secondary metabolites involved in defenses against pathogens. In this context, we aimed to determine whether oligosaccharidic elicitors differing in their capacity to activate defense-associated secondary metabolism in grapevine would differently impact primary metabolism. To answer this question, cell suspensions were treated with two elicitors: an oligogalacturonide, and the ß-glucan laminarin. Enzymatic activity assays together with targeted (HPLC) and global (GC-MS) analyses of metabolites were next performed to compare their impact on plant primary or secondary metabolism. The results showed that the oligogalacturonide, which induced the highest level of the phytoalexin resveratrol and the highest activity of stilbene synthase, also induced the highest activity of shikimate hydroxycinnamoyltransferase, a key enzyme involved in the synthesis of lignin. The oligogalacturonide-induced defenses had a significant impact on primary metabolism 24 h following elicitor treatment, with a reduced abundance of pyruvate and 2-oxoglutarate, together with an increase of a set of metabolites including carbohydrates and amino acids. Interestingly, an accumulation of galacturonate and gentiobiose was observed in the oligogalacturonide- and laminarin-treated cells, respectively, suggesting that both elicitors are rapidly hydrolyzed in grapevine cell suspension cultures.


Assuntos
Metaboloma/fisiologia , Células Vegetais/enzimologia , Proteínas de Plantas/metabolismo , Vitis/enzimologia , Vitis/citologia
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