SUMMARY
Introduction: Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is an airborne plant pathogen with a necrotrophic lifestyle attacking over 200 crop hosts worldwide. Although there are ...fungicides for its control, many classes of fungicides have failed due to its genetic plasticity. It has become an important model for molecular study of necrotrophic fungi.
Taxonomy: Kingdom: Fungi, phylum: Ascomycota, subphylum: Pezizomycotina, class: Leotiomycetes, order: Helotiales, family: Sclerotiniaceae, genus: Botryotinia.
Host range and symptoms: Over 200 mainly dicotyledonous plant species, including important protein, oil, fibre and horticultural crops, are affected in temperate and subtropical regions. It can cause soft rotting of all aerial plant parts, and rotting of vegetables, fruits and flowers post‐harvest to produce prolific grey conidiophores and (macro)conidia typical of the disease.
Pathogenicity: B. cinerea produces a range of cell‐wall‐degrading enzymes, toxins and other low‐molecular‐weight compounds such as oxalic acid. New evidence suggests that the pathogen triggers the host to induce programmed cell death as an attack strategy.
Resistance: There are few examples of robust genetic host resistance, but recent work has identified quantitative trait loci in tomato that offer new approaches for stable polygenic resistance in future.
Useful websites: http://www.phi‐base.org/query.php, http://www.broad.mit.edu/annotation/genome/botrytis_cinerea/Home.html, http://urgi.versailles.inra.fr/projects/Botrytis/, http://cogeme.ex.ac.uk
Sensitivity of B. cinerea to commonly used fungicides against Gray mold with emphasis to the newer quinone outside inhibitor (QoIs), and succinate dehydrogenase inhibitors (SDHIs) was assessed during ...a monitoring survey from vegetable greenhouses in four representative regions of Crete. 42% from a total of 168 isolates were simultaneously resistant to boscalid, fluopyram, pyraclostrobin and fenhexamid but not to fludioxonil making this phenylpyrrole fungicide an excellent anti-resistance antifungal agent. Isolates with double resistance to SDHIs and QoIs were found in very high frequencies indicating a selection towards double resistance due to the use of pyraclostrobin-boscalid mixtures. A number of sdhB resistance mutations (H272R, N230I and P225F/H) were found in isolates also carrying the G143A cytb resistance mutation in the above isolates. A novel sdhB point mutation (I274V) was identified for the first time in B. cinerea isolates collected from greenhouses with a fluopyram spray history with specific resistance to SDHIs. A PCR-RFLP diagnostic assay was developed for the detection of this mutation in the sdhB gene. Mutations P225F/H and I274V were found to be associated with fitness penalties in terms of mycelial growth, sporulation or pathogenicity. Results suggest that, in order to retain effective control of gray mold in Crete, appropriate anti-resistance strategies should be implemented taking into account the high double SDHI and QoI resistance frequencies. Additional studies for monitoring the already known and the new SDHI-resistance mutations, are necessary in order to hinder the further spread and establishment of single or double resistant isolates of B. cinerea detected in greenhouses in Crete.
Display omitted
•Botrytis cinerea Isolates with double resistance to SDHIs and QoIs were found in very high frequencies.•A number of resistance mutations in the sdhB subunit of the SDH gene were detected.•A PCR-RFLP diagnostic was developed for the detection of sdhB I274V mutation identified for the first time in B. cinerea.
Valorization of grape stems Ruiz-Moreno, María J.; Raposo, Rafaela; Cayuela, Jose M. ...
Industrial crops and products,
01/2015, Volume:
63
Journal Article
Peer reviewed
•An extract from grape stems was characterized.•Antioxidant and antimicrobial activities of the extract resulted high.•Odorant compounds found in the extract were similar to that found in wine.•Grape ...stem extract is an economic and promising alternative to SO2 in winemaking.•Grape stems are added-value byproducts.
The wine industry produces large amounts of grape stem byproducts, which have been described as a natural source of polyphenols. In the present study, an extract from grape stems was evaluated for its antioxidant and antimicrobial activities in model wine to determine its potential capacity to replace and/or reduce SO2 in winemaking. Additionally, its possible effects on aroma were studied.
Grape stem extract (STE) showed high antioxidant activity and it can be proposed as an energetic antioxidant. Its antimicrobial activity was compared to that of SO2. STE showed a lower inhibitory effect than SO2 for Saccharomyces cerevisiae, Hanseniaspora uvarum, Dekkera bruxellensis and Pediococcus damnosus whereas STE seems to be more efficient against Candida stellata and Botryotinia fuckeliana. GC–olfactometry analysis of STE showed that its most important odorants are naturally present in wines, and thus olfactometric profile modifications in wine, after STE addition, could appear quantitatively but not qualitatively.
It can be concluded that grape stems are compounds with a low sourcing cost, high antioxidant activity and good antimicrobial properties.
The grey mould fungus Botrytis cinerea causes losses of commercially important fruits, vegetables and ornamentals worldwide. Fungicide treatments are effective for disease control, but bear the risk ...of resistance development. The major resistance mechanism in fungi is target protein modification resulting in reduced drug binding. Multiple drug resistance (MDR) caused by increased efflux activity is common in human pathogenic microbes, but rarely described for plant pathogens. Annual monitoring for fungicide resistance in field isolates from fungicide-treated vineyards in France and Germany revealed a rapidly increasing appearance of B. cinerea field populations with three distinct MDR phenotypes. All MDR strains showed increased fungicide efflux activity and overexpression of efflux transporter genes. Similar to clinical MDR isolates of Candida yeasts that are due to transcription factor mutations, all MDR1 strains were shown to harbor activating mutations in a transcription factor (Mrr1) that controls the gene encoding ABC transporter AtrB. MDR2 strains had undergone a unique rearrangement in the promoter region of the major facilitator superfamily transporter gene mfsM2, induced by insertion of a retrotransposon-derived sequence. MDR2 strains carrying the same rearranged mfsM2 allele have probably migrated from French to German wine-growing regions. The roles of atrB, mrr1 and mfsM2 were proven by the phenotypes of knock-out and overexpression mutants. As confirmed by sexual crosses, combinations of mrr1 and mfsM2 mutations lead to MDR3 strains with higher broad-spectrum resistance. An MDR3 strain was shown in field experiments to be selected against sensitive strains by fungicide treatments. Our data document for the first time the rising prevalence, spread and molecular basis of MDR populations in a major plant pathogen in agricultural environments. These populations will increase the risk of grey mould rot and hamper the effectiveness of current strategies for fungicide resistance management.
The European Union is promoting regulatory changes to ban fungicides because of the impact their use has on the ecosystem and the adverse effects they can pose for humans. An ecofriendly alternative ...to these chemicals to fight against fungal species with low toxicity is essential oils and their compounds extracted from aromatic plants. The purpose of this study was to evaluate the in vitro antifungal capacity of the botanical compounds eugenol, carvacrol, thymol, and cinnamaldehyde, and the synergy or antagonism of their mixtures, against
and
. Different bioassays were performed at doses of 300, 200, 150, and 100 µg/mL using pure commercial compounds and their combination in potato dextrose agar culture medium. Growth rate and the mycelium growth inhibition parameters were calculated. Phenolic compounds and their combination inhibited the development of species at the different concentrations, with fungicidal or fungistatic activity shown under almost all the tested conditions. When comparing the growth rates of the species in the control plates and treatments, the statistical analysis showed that there were statistically significant differences. The mixture of compounds improved fungicidal activity against the studied species and at a lower concentration of monoterpenes.
Aiming at expanding the portfolio of Old Yellow Enzymes (OYEs), which have been systematically studied to be employed in the chemical and pharmaceutical industries as useful biocatalysts, we decided ...to explore the immense reservoir of filamentous fungi. We drew from the genome of the two Ascomycetes
and
four new members of the OYE superfamily belonging to the classical and thermophilic-like subfamilies. The two
OYEs show wider substrate spectra than the
OYE homologues, which appear as more specialized biocatalysts. According to their mesophilic origins, the new enzymes neither show high thermostability nor extreme pH optimums. The crystal structures of
OYE4 and
OYE8 have been determined, revealing the conserved features of the thermophilic-like subclass as well as unique properties, such as a peculiar N-terminal loop involved in dimer surface interactions. For the classical representatives
OYE1 and
OYE2, model structures were built and analyzed, showing surprisingly wide open access to the active site cavities due to a shorter β6-loop and a disordered capping subdomain.
Preventing deterioration and extending shelf life by using natural agents remain challenges in the distribution of premium‐quality blueberry. Herein, Botryotinia fuckeliana (B. fuckeliana) was ...isolated from the rotting postharvest blueberry and identified, and the causal pathogen was re‐isolated from the decay blueberry to confirm Koch's postulates. Experimental results indicated that spore germination and mycelial growth of B. fuckeliana, were significantly inhibited by chitosan in a concentration‐dependent mode. Application of chitosan coating to blueberry exhibited positive effect on the changes of weight loss, firmness, total phenolics and anthocyanins, as storage time increased. Hence, chitosan may be potentially applied in food industry for controlling the decay and extending the shelf life of postharvest blueberry.
Practical Applications
Blueberry has received considerable attention due to its content of health promoting micronutrients and several bioactive phytochemicals. However, it is often shortened by weight or moisture loss, and fungi infection under high humidity condition resulting in sensorial and nutritional changes. This study aims to provide experimental evidence for application of chitosan in the maintenance of quality (inhibits the microbial spoilage, retards weight loss, maintains the total phenolic and anthocyanin contents) of postharvest blueberry.
The cosmopolitan genus Botrytis contains 22 recognized species and one hybrid. The current classification is largely based on morphological characters and, to a minor extent, on physiology and host ...range. In this study, a classification of the genus was constructed based on DNA sequence data of three nuclear protein-coding genes (RPB2, G3PDH, and HSP60) and compared with the traditional classification. Sexual reproduction and the host range, important fitness traits, were traced in the tree and used for the identification of major evolutionary events during speciation. The phylogenetic analysis corroborated the classical species delineation. In addition, the hybrid status of B. allii (B. byssoidea x B. aclada) was confirmed. Both individual gene trees and combined trees show that the genus Botrytis can be divided into two clades, radiating after the separation of Botrytis from other Sclerotiniaceae genera. Clade 1 contains four species that all colonize exclusively eudicot hosts, whereas clade 2 contains 18 species that are pathogenic on either eudicot (3) or monocot (15) hosts. A comparison of Botrytis and angiosperm phylogenies shows that cospeciation of pathogens and their hosts have not occurred during their respective evolution. Rather, we propose that host shifts have occurred during Botrytis speciation, possibly by the acquisition of novel pathogenicity factors. Loss of sexual reproduction has occurred at least three times and is supposed to be a consequence of negative selection.
Summary
Lead is a priority pollutant, and lead metal is widely found in the environment as a waterproofing structural component in roofing, fence post covers, venting and flashing, as well as in ...industrial and urban waste. However, little is known of microbial interactions with metallic lead. The objective of this research was to investigate fungal roles in transformations of lead in a surface biofilm community growing on lead sheeting. The lead surface was found to support a diverse fungal community with several members, such as Aureobasidum pullulans, Phoma macrostoma, Penicillium sp. and Botryotinia fuckeliana, probably originating from adjacent phylloplane communities. Many fungal isolates showed tolerance to lead compounds in growth inhibition assays and were able to mediate production of lead‐containing secondary minerals in the presence of metallic lead. These exhibited widely differing morphologies to the lead‐containing secondary minerals produced under abiotic conditions. The presence of pyromorphite (Pb5(PO4)3Cl) (approximately 50 wt%) was detected in the lead sheet biofilm, and we speculate that animal (bird) faeces could be a significant source of phosphorus in this location. Pyromorphite formation represents biomineralization of mobile lead species into a very stable form, and this research provides the first demonstration of its occurrence in the natural environment.
PDF
