196,045 research outputs found
Development and assessment of plant protein hydrolysates as biopesticides against zucchini powdery mildew
No full textImproving BGP convergence with Fed4FIRE+ experiments
No full textThe Border Gateway Protocol (BGP) is the single routing protocol that glues the Internet together. Its performance, especially the convergence speed after path changes, is key to global efficiency, also in light of the fact that the number of Autonomous Systems (ASes) and Subnets has reached a level that makes path changes a frequent event. This work presents a testbed-based experimental analysis of BGP convergence time under different hypothesis of Minimum Route Advertisement Interval (MRAI) setting and a proposal to improve it by setting MRAI based on the topological position of the ASes. MRAI is a timer that regulates the frequency of successive UPDATE messages sent by a BGPs router for a given route and destination. The work is based on the modifications of the BIRD BGP daemon and shows that it is possible to execute experiments on testbeds with topologies that have Internet-like characteristics scaling up to thousands of ASes
The effect of hydrolysis and protein source on the efficacy of protein hydrolysates as plant resistance inducers against powdery mildew
No full textThe substitution of synthetic pesticides has become a priority in agriculture and the induction of plant resistance by protein hydrolysates may offer a sustainable alternative. The protein source, method and degree of hydrolysis, as well as the amino acid and peptide composition may affect the efficacy of protein hydrolysates against plant diseases. The aim of our work was to clarify the effect of enzymatic and acid hydrolysis on various plant protein sources (soybean, rapeseed and guar protein meal), in term of efficacy against courgette powdery mildew. The enzymatic hydrolysates were produced using Alcalase or Flavourzyme at 1 and 50% enzyme/substrate ratio at 50°C for 24 h. The acid hydrolysates were obtained using 6N H2SO4 for 15 min at 121°C (6N A) or for 8 h at 100°C (6N B). Preventive foliar treatments with guar Alcalase 50% and 6N B hydrolysates significantly reduced disease symptoms compared to the non-hydrolysed protein source. A positive correlation was found between efficacy and the degree of hydrolysis of guar acid hydrolysates, suggesting that this hydrolysis method may enhance the functional properties of the original protein source. Moreover, our analysis revealed positive correlations between the efficacy of guar hydrolysates and concentrations of specific peptides and amino acids. Our results showed that the biocontrol effect of plant protein hydrolysates was related to the original protein source, and two specific hydrolysis processes improved the functional properties of guar, producing peptide fragments and free amino acids that may be involved in the regulation of innate immune response in plants
The efficacy of plant-derived protein hydrolysates against zucchini powdery mildew is affected by their biochemical characteristics
No full textFoliar and root applications of the rare sugar tagatose control powdery mildew in soilless grown cucumbers
No full textBiodegradation of a mixture of PAHs was assessed in forest soil microcosms performed either without or
with bioaugmentation using individual fungi and bacterial and a fungal consortia. Respiratory activity,
metabolic intermediates and extent of PAH degradation were determined. In all microcosms the low
molecular weight PAH’s naphthalene, phenanthrene and anthracene, showed a rapid initial rate of
removal. However, bioaugmentation did not significantly affect the biodegradation efficiency for these
compounds. Significantly slower degradation rates were demonstrated for the high molecular weight
PAH’s pyrene, benz[a]anthracene and benz[a]pyrene. Bioaugmentation did not improve the rate or extent
of PAH degradation, except in the case of Aspergillus sp. Respiratory activity was determined by CO2 evolution
and correlated roughly with the rate and timing of PAH removal. This indicated that the PAHs were
being used as an energy source. The native microbiota responded rapidly to the addition of the PAHs and
demonstrated the ability to degrade all of the PAHs added to the soil, indicating their ability to remediate
PAH-contaminated soils
Protein-based products as resistance inducers: disease control and mechanisms of action
No full textLeaf treatments with a protein derivative represent a sustainable strategy in plant protection, because they induce grapevine resistance, and change the structure of leaf microbial communities on grapevine. Plant-protein hydrolysates reduce powdery mildew severity, and their biocontrol activity is affected by the protein source, degree of hydrolysis and peptide composition
Effect of a Wood-Based Carrier of <i>Trichoderma atroviride</i> SC1 on the Microorganisms of the Soil
No full textWood pellets can sustain the growth of Trichoderma spp. in soil; however, little is known about their side effects on the microbiota. The aims of this study were to evaluate the effect of wood pellets on the growth of Trichoderma spp. in bulk soil and on the soil microbial population’s composition and diversity. Trichoderma atroviride SC1 coated wood pellets and non-coated pellets were applied at the level of 10 g∙kg−1 of soil and at the final concentration of 5 × 103 conidia∙g−1 of soil and compared to a conidial suspension applied at the same concentration without the wood carrier. Untreated bulk soil served as a control. The non-coated wood pellets increased the total Trichoderma spp. population throughout the experiment (estimated as colony-forming unit g−1 of soil), while wood pellets coated with T. atroviride SC1 did not. The wood carrier increased the richness, and temporarily decreased the diversity, of the bacterial population, with Massilia being the most abundant bacterial genus, while it decreased both the richness and diversity of the fungal community. Wood pellets selectively increased fungal species having biocontrol potential, such as Mortierella, Cladorrhinum, and Stachybotrys, which confirms the suitability of such carriers of Trichoderma spp. for soil application
A protein derivative stimulates grapevine resistance and the natural phyllosphere microbiota against downy mildew
No full textProtein derivatives can stimulate plant growth, activate plant resistance and act as
nutritional substrate for phyllosphere microbial communities. A protein derivative (nutrient
broth, NB) reduced downy mildew symptoms and induced the expression of defence-related
genes, indicating the activation of grapevine resistance mechanisms. NB increased the
number of culturable phyllosphere bacteria and altered the composition of bacterial and
fungal populations residing on grapevine leaves. Modifications in the structure of
phyllosphere populations caused by NB application could partially contribute to downy
mildew control by competition for space or other biocontrol strategies. Modifying
phyllosphere populations by increasing natural biocontrol agents with the application of
microbial nutrients can open new opportunities in terms of biocontrol strategie
Tagatose suppresses grapevine powdery mildew and downy mildew under field conditions with no severe impacts on grape must fermentation
No full textBackground and Aims. Grapevine is susceptible to several diseases and requires a large use of fungicides. Sustainable alternatives
must be safe for humans and the environment and also should not interfere with must fermentation. (e aim of this study was to
implement the use of a rare sugar, tagatose, against powdery mildew and downy mildew and to assess possible side e0ects on
Saccharomyces cerevisiae fermentation. Methods and Results. Tagatose was evaluated for the suppression of powdery mildew and
downy mildew under controlled and 2eld conditions and for its impact on S. cerevisiae fermentation of synthetic and grape musts.
Tagatose applied at 8 kg/hareduced powdery mildew and downy mildew severity and incidence on grapevine leaves and bunches
under 2eld conditions. Tagatose caused a limited and transient slowdown of the fermentation with no negative impact on yeast
viability and wine chemical composition at the end of the fermentation. Conclusions. Tagatose is a promising alternative for
sustainable grapevine protection against powdery mildew and downy mildew with no negative impacts on the must fermentation.
Signi/cance of the Study. (ese 2ndings pave the way for grapevine protection strategies based on the use of rare sugars as
sustainable fungicides in integration with other plant protection products
Ecological impact of a rare sugar on grapevine phyllosphere microbial communities
No full textPlants host a complex microbiota inside or outside their tissues, and phyllosphere microorganisms can be influenced by environmental, nutritional and agronomic factors. Rare sugars are defined as monosaccharides with limited availability in nature and they are metabolised by only few certain microbial taxa. Among rare sugars, tagatose (TAG) is a low-calories sweetener that stimulates and inhibits beneficial and pathogenic bacteria in the human gut microbiota, respectively. Based on this differential effect on human-associated microorganisms, we investigated the effect of TAG treatments on the grapevine phyllosphere microorganisms to evaluate whether it can engineer the microbiota and modify the ratio between beneficial and pathogenic plant-associated microorganisms. TAG treatments changed the structure of the leaf microbiota and they successfully reduced leaf infections of downy mildew (caused by Plasmopara viticola) and powdery mildew (caused by Erysiphe necator) under field conditions. TAG increased the relative abundance of indigenous beneficial microorganisms, such as some potential biocontrol agents, which could partially contribute to disease control. The taxonomic composition of fungal and bacterial leaf populations differed according to grapevine locations, therefore TAG effects on the microbial structure were influenced by the composition of the originally residing microbiota. TAG is a promising biopesticide that could shift the balance of pathogenic and beneficial plant-associated microorganisms, suggesting selective nutritional/anti-nutritional properties for some specific taxa. More specifically, TAG displayed possible plant prebiotic effects on the phyllosphere microbiota and this mechanism of action could represent a novel strategy that can be further developed for sustainable plant protectio
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