Etude de la phyllosphère et de sa réponse au biostimulant foliaire

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Biostimulation de la vigne, l’action d’un filtrat d’algues. Évaluation et explication des effets du filtrat d’algues (GoActiv) à base d’Ascophyllum nodosum sur la qualité de la vendange.

Article dans une revue professionnelleContexte - Le biostimulant de Goëmar à base d’algues nommé « filtrat d’algues (GoActiv) » utilisé en encadrement de floraison de la vigne a des effets bénéfiques lors de sa période d’application. Mais des effets plus tardifs, jusqu’à la vendange, en particulier sur le taux d’anthocyanes du raisin noir, ont été rapportés. Ce point devait être élucidé. Travail - Une étude a donc été menée dans le Bordelais, sur cépage merlot, par l’université de Bordeaux, durant trois années. Elle a consisté à évaluer les effets du filtrat d’algues jusqu’à la vendange et à élucider leurs mécanismes au niveau de l’expression des gènes impliqués dans la synthèse des composés phénoliques, dont les anthocyanes. Résultats - Une accélération de la synthèse des anthocyanes a été démontrée. Elle facilite le choix de la date de vendange. Par ailleurs, la stimulation de l’expression de deux gènes a été mise en évidence. L’un d’eux intervient au début de la biosynthèse des composés phénoliques au stade bouton floral, le second agit sur la synthèse des anthocyanes à partir de la véraison

Prebiotics’ application as an agroecological approach to improve plant growth, soil conditions, and carbon sequestration

Soil fertility and productivity are severely impacted by exploitation and degradation processes. These threats, coupled with population growth and climatic changes, force us to search for innovative agroecological solutions. Prebiotics are one type of soil biostimulants that are used to enhance soil conditions, plant growth, and could contribute to improve carbon sequestration. In this context, our study was designed to evaluate and explain the effects of two commercial prebiotics (K1® and NUTRIGEO L®) applied on agricultural soil mixed with organic wheat straws and cultivated with Zea mays L. in comparison to the same planted soil but untreated (control). Analysis were performed at two harvesting dates after the prebiotics’ application (3 weeks D1 and 10 weeks D2). For that, we monitored plant growth criteria, soil physico-chemical parameters, soil organic matter (OM) evolution, and soil microbial community structure and diversity with emphases on indigenous microbial selection and root mycorrhization. The obtained results demonstrated the short- and medium-term positive effects of prebiotics on soil fertility and microbial community and their repercussions on plant biomass and carbon storage. Our aim is to confirm the vital role prebiotics will play as a new alternative approach in the agroecological transition toward modern, durable, and sustainable agriculture

Prebiotics: A Solution for Improving Plant Growth, Soil Health, and Carbon Sequestration?

Abstract Soil fertility and productivity are severely impacted by exploitation and degradation processes. These threats, coupled with population growth and climatic changes, compel us to search for innovative agroecological solutions. Prebiotics, a type of soil biostimulant, are used to enhance soil conditions and plant growth and may play a role in carbon (C) sequestration. Two commercial prebiotics, K1® and NUTRIGEO L® (referred to as SPK and SPN, respectively), were assessed for their effects on agricultural soil cultivated with Zea mays L., compared to untreated soil or control (SP). Analyses were performed at two harvesting dates: three weeks (D1) and ten weeks (D2) after the application of prebiotics. Plant growth parameters and soil characteristics were measured, focusing on soil organic matter, soil bacterial and fungal communities, and plant root mycorrhization. Regarding physicochemical parameters, both prebiotic treatments increased soil electrical conductivity, cation exchange capacity, and soluble phosphorus (P) while decreasing nitrates. Meanwhile, the SPN treatment was distinct in elevating specific cationic minerals, such as calcium (Ca) and boron (B), at D2. At the microbial level, each prebiotic induced a unique shift in the indigenous bacterial and fungal communities’ abundance and diversity, evident at D2. Simultaneously, specific microbial taxa were recruited by each prebiotic treatment, such as Caulobacter , Sphingobium , and Massilia from bacteria and Mortierella globalpina and Schizothecium carpinicola from fungi in SPK as well as Chitinophaga , Neobacillus , and Rhizomicrobium from bacteria and Sordariomycetes and Mortierella minutissima from fungi in SPN. These biomarkers were identified as (a) saprotrophs, (b) plant growth-promoting bacteria and fungi, (c) endohyphal bacteria, and (d) endophytic and symbiotic microbiota. This result was reflected in the increase in glomalin content and mycorrhization rate in the treated soils, especially by SPN. We observed that these effects led to an increase in plant biomass (shoots by 19% and 22.8% and roots by 47.8% and 35.7% dry weights for SPK and SPN, respectively) and contributed to an increase in soil C content (organic C by 8.4% and total C by 8.9%), particularly with SPN treatment. In light of these findings, the use of prebiotics ten weeks after application not only increased plant growth by improving soil characteristics and shaping its native microbial community but also demonstrated the potential to enhance C sequestration

Prebiotics' application as an agroecological approach to improve plant growth, soil conditions, and carbon sequestration

Soil fertility and productivity are severely impacted by exploitation and degradation processes. These threats, coupled with population growth and climatic changes, force us to search for innovative agroecological solutions. Prebiotics are one type of soil biostimulants that are used to enhance soil conditions, plant growth, and could contribute to improve carbon sequestration. In this context, our study was designed to evaluate and explain the effects of two commercial prebiotics (K1® and NUTRIGEO L®) on soil mixed with organic wheat straws and cultivated with Zea mays L. in comparison to untreated soil at two harvesting dates after their application (3 weeks D1 and 10 weeks D2). For that, we monitored plant growth criteria, soil physico-chemical parameters, soil organic matter (OM) evolution, and soil microbial community structure and diversity with emphases on indigenous microbial selection and root mycorrhization. The obtained results demonstrated the short- and medium-term positive effects of prebiotics on soil fertility and microbial community and their repercussions on plant biomass and carbon storage. Our aim is to confirm the vital role prebiotics will play as a new alternative approach in the agroecological transition toward modern, durable, and sustainable agriculture

Water extracts from winery by-products as tobacco defense inducers

EcotoxicologyISI Document Delivery No.: AP6TNTimes Cited: 1Cited Reference Count: 31Benouaret, Razik Goujon, Eric Trivella, Aurelien Richard, Claire Ledoigt, Gerard Joubert, Jean-Marie Mery-Bernardon, Aude Goupil, PascaleFUI: Fonds Unique InterministerielThis work had financial support provided by grants from FUI: Fonds Unique Interministeriel. We thank Celine Sac for her help in growing tobacco plants and Dominique Marcon for the tobacco leaf images.SpringerDordrechtWater extracts from winery by-products exhibited significant plant defense inducer properties. Experiments were conducted on three marc extracts containing various amounts of polyphenols and anthocyanins. Infiltration of red, white and seed grape marc extracts into tobacco leaves induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining. The infiltration zones and the surrounding areas revealed accumulation of autofluorescent compounds under UV light. Leaf infiltration of the three winery by-product extracts induced defense gene expression. The antimicrobial PR1, beta-1,3-glucanase PR2, and chitinase PR3 target genes were upregulated locally in tobacco plants following grape marc extract treatments. The osmotin PR5 transcripts accumulated as well in red marc extract treated-tobacco leaves. Overall, the winery by-product extracts elicited an array of plant defense responses making the grape residues a potential use of high value compounds

Potentiel des microorganismes de la phyllosphère et influence de l’application de produit foliaire

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