Percorrer por autor "Reis, Francisca"
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- Bacteria could help ectomycorrhizae establishment under climate variationsPublication . Reis, Francisca; Magalhães, Alexandre P.; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, TeresaRhizosphere microbiome is one of the main sources of plant protection against drought. Beneficial symbiotic microorganisms, such as ectomycorrhizal fungi (ECMF) and mycorrhiza helper bacteria (MHB), interact with each other for increasing or maintaining host plant fitness. This mutual support benefits all three partners and comprises a natural system for drought acclimation in plants. Cork oak (Quercus suber L.) tolerance to drought scenarios is widely known, but adaptation to climate changes has been a challenge for forest sustainability protection. In this work, ECMF and MHB communities from cork oak forests were cross-linked and correlated with climates. Cenococcum, Russula and Tuber were the most abundant ECMF capable of interacting with MHB (ECMF~MHB) genera in cork oak stands, while Bacillus, Burkholderia and Streptomyces were the most conspicuous MHB. Integrating all microbial data, two consortia Lactarius/Bacillaceae and Russula/Burkholderaceae have singled out but revealed a negative interaction with each other. Russula/Burkholderaceae might have an important role for cork oak forest sustainability in arid environments, which will be complemented by the lower drought adaptation of competitive Lactarius/Bacillaceae. These microbial consortia could play an essential role on cork oak forest resilience to upcoming climatic changes.
- Climatic impacts on the bacterial community profiles of cork oak soilsPublication . Reis, Francisca; Soares-Castro, Pedro; Costa, Daniela; Tavares, Rui Manuel; Baptista, Paula; Santos, Pedro M.; Lino-Neto, TeresaClimate changes comprise increasing global temperature and water cycle deregulation (precipitation storms and long dry seasons). Many affected ecosystems are located within the Mediterranean basin, where cork oak (Quercus suber L.) is one of the most important forest ecosystems. Despite cork oak tolerance to drought, the decrease of water availability and increase of temperature is causing a serious decline of cork oak populations. In the present work, the bacterial community of cork oak soils was assessed by metabarcoding using Illumina Miseq. Soils from seven independent cork oak forests were collected along a climate gradient. In all forest soils, Proteobacteria and Actinobacteria were the richest and more abundant bacteria. Acidobacteria also presented a high relative abundance, and Chloroflexi was a rich phylum. The soil bacterial community diversity and composition was strongly affected by the climatic region where cork oak resides and specific bacterial taxa were differently affected by precipitation and temperature. Accordingly, cork oak bacterial communities clustered into three distinct groups, related with humid, sub-humid and arid/semi-arid climates. Driest and warmer forests presented more diverse bacterial communities than humid and coolest forests. However, driest climates presented more homogenous bacterial communities among forests than humid climates. Climate (mainly precipitation) revealed to be the strongest driver leading to significant variations of bacterial community profiles. The most impacted bacterial taxa by climatic variables were Proteobacteria, in particular Gammaproteobacteria and Deltaproteobacteria, Chloroflexi, and Firmicutes. Humid forests presented mainly Acidobacteria as good indicators of climate, whereas Actinobacteria members were better indicators for arid forests (mainly Gaiellales and Frankiales). Some indicator species for different climate conditions were members of the bacterial core of cork oak stands (7% of the total bacterial community). Taken together, different microbiomes were selected by the climate conditions in cork oak stands along a climate gradient and might provide the key to forest sustainability in times of global warming.
- Cork oak forests soil bacteria: Potential for sustainable agroforest productionPublication . Reis, Francisca; Pereira, Ana João; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, TeresaPlant growth promoting rhizobacteria (PGPR) are in increasing demand due to their role in promoting sustainable practices, not only in agriculture but also in forestry. Keeping in mind the future application of PGPR for increasing cork oak sustainability, the aim of this study was to find cork oak PGPR isolates with increased nutrient solubilisation traits, able to promote root morphological changes and/or antagonize cork oak bark phytopathogens. Soils from three cork oak forests with distinct bioclimates (humid, semi†humid and semi†arid) were used for isolating bacteria. From the 7634 colony†forming units, 323 bacterial isolates were biochemically assayed for PGPR traits (siderophores production, phosphate solubilizing and organic acids production), and 51 were found to display all these traits. These PGPR were able to induce root morphological changes on Arabidopsis thaliana, like suppression of primary root growth, increase of lateral roots or root hairs formation. However, the most proficient PGPR displayed specific ability in changing a single root morphological trait. This ability was related not only to bacterial genotype, but also with the environment where bacteria thrived and isolation temperature. Bacteria from semi†arid environments (mainly Bacillus megaterium isolates) could hold a promising tool to enhance plant development. Other isolates (Serratia quinivorens or B. cereus) could be further explored for biocontrol purposes.
- Ectomycorrhizal fungal diversity and community structure associated with cork oak in different landscapesPublication . Reis, Francisca; Valdiviesso, Teresa; Varela, Carolina; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, TeresaCork oak (Quercus suber L.) forests play an important ecological and economic role. Ectomycorrhizal fungi (ECMF) are key components for the sustainability and functioning of these ecosystems. The community structure and composition of ECMF associated with Q. suber in different landscapes of distinct Mediterranean bioclimate regions have not previously been compared. In this work, soil samples from cork oak forests residing in different bioclimates (arid, semi-arid, sub-humid, and humid) were collected and surveyed for ectomycorrhizal (ECM) root tips. A global analysis performed on 3565 ECM root tips revealed that the ECMF community is highly enriched in Russula, Tomentella, and Cenoccocum, which correspond to the ECMF genera that mainly contribute to community differences. The ECMF communities from the rainiest and the driest cork oak forests were distinct, with soils from the rainiest climates being more heterogeneous than those from the driest climates. The analyses of several abiotic factors on the ECMF communities revealed that bioclimate, precipitation, soil texture, and forest management strongly influenced ECMF structure. Shifts in ECMF with different hyphal exploration types were also detected among forests, with precipitation, forest system, and soil texture being the main drivers controlling their composition. Understanding the effects of environmental factors on the structuring of ECM communities could be the first step for promoting the sustainability of this threatened ecosystem.
- Fungal community in chestnut orchards with different Hypholoma fasciculare aboveground abundance: potential implications for sustainable productionPublication . Reis, Francisca; Pereira, Eric Carvalho; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, TeresaEuropean chestnut (Castanea sativa Mill.) trees have a significant impact in the Portuguese economy, due to the production of chestnuts and wood, and other related activities, such as mushroom collection and hunt. Hypholoma fasciculare (Huds.) is a saprophytic fungus widely distributed in Trás-os-Montes (northeast of Portugal) chestnut groves that displays an in vitro strong antagonistic activity against ectomycorrhizal (EMC) fungi. In this study, the above- and belowground fungal diversity was evaluated in three chestnut orchards, containing distinct H. fasciculare sporocarps abundances in an attempt to better understand the potential of this fungus to attain an improved chestnut tree sustainable productivity. Aboveground analysis was performed based on macrofungi collection during fruiting seasons (spring and autumn) of two consecutive years. Belowground evaluation was based on the metabarcoding of chestnut orchards soil DNA, using the fungal barcode ITS1 and a high-throughput sequencing (454-sequencing) approach. Although all collected fruitbodies were identified as being produced by Basidiomycota fungi, a more diversified fungal community was revealed by the belowground approach. Both approaches have revealed a rich and abundant ECM community in all chestnut orchards. The correlation between the abundance of H. fasciculare fruitbodies and specific fungal guilds fruitbodies/reads suggests that this fungus may affect soil fungal community, mainly ECM and phytoparasites, as well as species composition of fungal communities. Although not conclusive, the results suggest that H. fasciculare presence could be critical for sustainable chestnut ecosystems.
- In vitro interactions between the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare fungi: morphological aspects and volatile productionPublication . Baptista, Paula; Pinho, P. Guedes de; Moreira, Nathalie; Malheiro, Ricardo; Reis, Francisca; Padrão, Jorge; Tavares, Rui Manuel; Lino-Neto, TeresaEctomycorrhizal fungi are crucial for forests sustainability. For Castanea sativa, ectomycorrhizal fungus Pisolithus tinctorius is an important mutualist partner. Saprotrophic fungi Hypholoma fasciculare, although used for biocontrol of Armillaria root disease, it negatively affected the interaction between the P. tinctorius and plant host roots, by compromise the formation of P. tinctorius-C. sativa mycorrhizae. In this work, fungal morphology during inhibition of H. fasciculare against P. tinctorius was elucidated. P. tinctorius growth was strongly affected by H. fasciculare, which was significantly reduced after six days of co-culture and become even more significant through time. During this period, P. tinctorius developed vesicles and calcium oxalate crystals, which were described as mechanisms to stress adaption by fungi. H. fasciculare produced different volatile organic compounds in co-cultures over time and differ between single or in dual-species. H. fasciculare highly produced sesquiterpenes (namely, α-muurolene) and nitrogen-containing compounds, which are recognised as having antimicrobial activity.
- Mycorrhization of fagaceae forests within mediterranean ecosystemsPublication . Reis, Francisca; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, TeresaMediterranean Fagaceae forests are valuable due to their ecological and socioeconomic aspects. Some profitable plant species, such as Castanea (timber and chestnut), Quercus (timber and cork), and Fagus (timber), encounter in this habitat the excellent edaphoclimatic conditions to develop. All Fagaceae plants are commonly associated to ECM fungal species, which are found in these forests in quite stable communities, mainly enriched in Russulaceae and Telephoraceae species. Currently, the Mediterranean Basin is considered as one of the global biodiversity hotspots, since many of their endemic plant species are not found elsewhere and are now under threat. Due to climate changing and introduction of disease agents, Fagaceae forests are facing an adaptation challenge to both biotic and abiotic threats. Although ECM communities are highly disturbed by climate factors and tree disease incidence, they could play an important role in increasing water availability to the plant and also improving plant tree defense against pathogens. Recent advances, namely, on genomics and transcriptomics, are providing tools for increasing the understanding of Fagaceae mycorrhization process and stress responses to biotic and abiotic stresses. Such studies can provide new information for the implementation of the most adequate management policies for protecting threaten Mediterranean forests.
- A new effective assay to detect antimicrobial activity of filamentous fungiPublication . Pereira, Eric Carvalho; Santos, A.; Reis, Francisca; Tavares, Rui Manuel; Baptista, Paula; Lino-Neto, Teresa; Almeida-Aguiar, CristinaThe search for new antimicrobial compounds and the optimization of production methods turn the use of antimicrobial susceptibility tests a routine. The most frequently used methods are based on agar diffusion assays or on dilution in agar or broth. For filamentous fungi, the most common antimicrobial activity detection methods comprise the co-culture of two filamentous fungal strains or the use of fungal extracts to test against single-cell microorganisms. Here we report a rapid, effective and reproducible assay to detect fungal antimicrobial activity against single-cell microorganisms. This method allows an easy way of performing a fast antimicrobial screening of actively growing fungi directly against yeast. Because it makes use of an actively growing mycelium, this bioassay also provides a way for studying the production dynamics of antimicrobial compounds by filamentous fungi. The proposed assay is less time consuming and introduces the innovation of allowing the direct detection of fungal antimicrobial properties against single cell microorganisms without the prior isolation of the active substance(s). This is particularly useful when performing large screenings for fungal antimicrobial activity. With this bioassay, antimicrobial activity of Hypholoma fasciculare against yeast species was observed for the first time.
- Soil DNA pyrosequencing and fruitbody surveys reveal contrasting diversity for various fungal ecological guilds in chestnut orchardsPublication . Baptista, Paula; Reis, Francisca; Pereira, Eric Carvalho; Tavares, Rui Manuel; Santos, Pedro M.; Richard, Franck; Selosse, Marc André; Lino-Neto, TeresaFungal diversity in Mediterranean forest soils is poorly documented, particularly when considering saprobic and pathogenic organisms. Next-generation sequencing (NGS) methods applied to soil fungi provide the opportunity to unveil the most inconspicuous functional guilds (e.g. saprobes) and life forms (e.g. Corticiaceae) of this tremendous diversity. We used fruitbody surveys over 2 years and soil 454 metabarcoding in Castanea sativa orchards to evaluate res pectively the reproductive (fruitbodies) and vegetative (mycelia) parts of fungal communities in three 100-year-old stands. Analysis of 839 fruitbodies and 210291 ITS1 reads revealed high fungal diversity, mainly shown by belowground analysis, with high (dominant) abundance of mycorrhizal fruitbodies and reads. Both methods displayed contrasted composition and structure of fungal communities, with Basidio- and Ascomycetes dominating above- and belowground, respectively. For the two dominant fungal guilds (i.e. ectomycorrhizal and saprobic), diversity above- and belowground overlapped weakly. This study is the first assessment of the complementarity of fruitbody surveys and NGS for analysing fungal diversity in Mediterranean ecosystems and shows that belowground methods still need to be completed by fruiting diversity to provide a comprehensive overview of the different fungal guilds. The results shed light on chestnut soil biodiversity and question the spatial distribution and synergies among fungal guilds.