Facilitating green care improvements in viticulturePaolo Sivilotti
, Tjaša Jug
, Urban Česnik
, Adesida Rowland
, Melita Sternad Lemut
, Lorena Butinar
, Urška Vrhovšek
, 2019, published scientific conference contribution
Abstract: The growing demand of consumers for environment-friendly and safe food products already forced many winemakers to restrict the application of synthetic fungicides to earlier season, trying to reduce the risk of residues being detected in wines. Main risk for infection by B. cinerea, however, occurs later in the season. To support an improvement in whole-season B. cinerea green care, the potential of yeasts as biocontrol agent (PBA) was studied. Selected yeasts were tested for their antifungal activities. Furthermore, a field experiment in Pinot noir and Pinot gris vineyards was designed to study different combinations of optimized canopy microclimate manipulation (CMM) techniques and PBA application. In experimental conditions, PBA's ability to maintain appropriate population density for disease prevention was observed. Grape and wine quality parameters were evaluated. Analytical approach of metabolomics was applied to upgrade the understanding of potentially induced changes in plant metabolism.
Based on yeasts testing results, biocontrol yeast P. guilliermondii ZIM 624 was selected and after its field application, we were able to detect its suitable density on grapes until harvest. In case of early defoliation for both varieties smaller grape compactness was confirmed together with lower yield. Among grape basic quality parameters, optimized techniques showed positive effect on sugar content, but unexpectedly, in the treatments with biocontrol yeasts the trends toward higher acidity were noticed in Pinot gris. CMM and PBA introduction indicated some effects on grapevine biosynthetic behaviour but the differences in content of these metabolites compared to control were poorly detected in final wines with exception of mainly some flavonols, stilbenes and flavan-3-ols (and consequently total phenolic content).
Found in: ključnih besedah
Summary of found: ...but the differences in content of these metabolites compared to control were poorly detected in...
Keywords: sustainable viticulture, Botrytis cinerea, yeasts, biocontrol, canopy microclimate manipulation, metabolomics, grapevine metabolites
Published: 28.02.2020; Views: 2132; Downloads: 0
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Diversity of bacteria and bacterial products as antibiofilm and antiquorum sensing drugs against pathogenic bacteriaFazlurrahman Khan
, Sandra Oloketuyi
, Young-Mog Kim
, 2019, review article
Abstract: The increase in antibiotic resistance of pathogenic bacteria has led to the development of new therapeutic approaches to inhibit biofilm formation as well as interfere quorum sensing (QS) signaling systems. The QS system is a phenomenon in which pathogenic bacteria produce signaling molecules that are involved in cell to cell communication, production of virulence factors, biofilm maturation, and several other functions. In the natural environment, several non-pathogenic bacteria are present as mixed population along with pathogenic bacteria and they control the behavior of microbial community by producing secondary metabolites. Similarly, non-pathogenic bacteria also take advantages of the QS signaling molecule as a sole carbon source for their growth through catabolism with enzymes. Several enzymes are produced by bacteria which disrupt the biofilm architecture by degrading the composition of extracellular polymeric substances (EPS) such as exopolysaccharide, extracellular- DNA and protein. Thus, the interference of QS system by bacterial metabolic products and enzymatic catalysis, modification of the QS signaling molecules as well as enzymatic disruption of biofilm architecture have been considered as the alternative therapeutic approaches. This review article elaborates on the diversity of different bacterial species with respect to their metabolic products as well as enzymes and their molecular modes of action. The bacterial enzymes and metabolic products will open new and promising perspectives for the development of strategies against the pathogenic bacterial infections.
Found in: ključnih besedah
Summary of found: ...behavior of microbial community by producing secondary metabolites. Similarly, non-pathogenic bacteria also take advantages of...
Keywords: Bacteria, biofilm, quorum sensing, inhibition, metabolites, pathogen, virulence.
Published: 18.01.2021; Views: 1264; Downloads: 0
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Berry primary and secondary metabolites in response to sunlight and temperature in the grapevine fruit zoneGuillaume Antalick
, Anne Pellegrino
, Alain Deloire
, Suzy Y. Rogiers
, 2020, professional article
Abstract: The chemical composition of berries at harvest, which will affect wine styles, is determined by complex physiological processes occurring from set through the fruit’s lifetime to maturity, and this is closely intertwined with environmental and crop management factors. Among those factors, climatic conditions within the fruit zone (i.e. microclimate), such as light and temperature, are well-known to aﬀect the physiology of the fruit at the skin, pulp and seed levels. This article will present the potential of leaf thinning in the bunch zone to modify cluster microclimate and berry composition.
Found in: ključnih besedah
Keywords: berry primary metabolites, berry secondary metabolites, fruit zone, sunlight, temperature
Published: 21.09.2021; Views: 685; Downloads: 22
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Unravelling the molecular basis of hydroxyapatite weathering driven by the ectomycorrhizal fungus Paxillus involutusChristina Paparokidou
, 2018, doctoral dissertation
Abstract: Ectomycorrhizal fungi (EMF) form symbiotic partnerships with tree roots and are able to chemically weather inorganic phosphorus (Pi)-rich minerals, supplying Pi to their host in return for photosynthates. The fungal-driven nutrient cycling from mineral weathering plays a pivotal role in ecosystems and crops productivity, as well as geochemical cycles. The aim of the study presented in this thesis is to unravel the molecular mechanisms by which the EM fungus Paxillus involutus weathers the Pi-rich mineral hydroxyapatite (HAP), either non-symbiotically or in symbiosis with its host tree Pinus sylvestris. Development of an artificial system to study P. involutus responses to varying concentration of Pi led to the identification of five high-affinity Pi transporter genes, of which the expression varies in an inversely proportional manner to Pi availability. Using the same system, whole-transcriptomic data from fungal hyphae unravelled the molecular basis of the EMF ability in Pi uptake at the global gene scale, revealing that EM symbiosis can directly affect Pi-responsive fungal genes such as the Pi transporter PiPT4. A second artificial system was used to study HAP solubilisation driven by P. involutus, which was confirmed by EDX spectroscopy data showing depletion of Pi from the HAP crystals, along with secondary minerals formation. Whole-transcriptomic analysis revealed that EM symbiosis induces a different set of HAP weathering genes in P. involutus hyphae, compared to the fungus growing non-symbiotically, including the specific expression of organic acid metabolic genes, which resulted in enhanced HAP solubilisation. Metabolomic analysis led to the identification of multiple secreted metabolites enriched in the presence of HAP in P. involutus systems grown non-symbiotically or in symbiosis with P. sylvestris seedlings. The analysis also led to the identification of putative novel fungal weathering agents. Results from transcriptomic and metabolomic analyses were ultimately combined in a model of HAP weathering by P. involutus.
Found in: ključnih besedah
Summary of found: ...led to the identification of multiple secreted metabolites enriched in the presence of HAP in...
Keywords: Paxillus involutus, Pinus sylvestris, ectomycorrhizal symbiosis, hydroxyapatite, SEM-EDX, fungal mineral weathering, fungal weathering metabolites, RNA-seq, UPLC-Q-TOF-MS
Published: 03.05.2022; Views: 237; Downloads: 0
Fulltext (33,58 MB)