Browsing by Author "Ramos, Miguel"
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- Degradation of 3-fluorophenol and Sodium Trifluoroacetate by Ectomycorrhizal fungiPublication . Franco, Albina R.; Ramos, Miguel; Sousa, Nadine R.; Silva, Débora S.; Oliveira, Rui S.; Castro, Paula M. L.
- Detection and quantification by real-time PCR of ectomycorrhizal fungi in inoculum formulations for urban trees applicationPublication . Serafim, Cindy; Ramos, Miguel; Castro, Paula Lima; Sousa, NadineBackground: Urban trees are key elements in mitigating the common environmental problems in urban areas, through provisioning crucial ecosystem services such as air quality improvement, decrease of water runoff and microclimate mitigation. Because of their well-known host tree benefits, Ectomycorrhizal Fungi (EcM) may play an important role in urban tree management, improving tree vigor, and thus the extent and resilience of ecosystem services delivered by urban trees under stress. Therefore it is important to develop dedicated EcM-inocula to improve urban tree health and its associated ecosystem service delivery. To support the study of the effect of inoculum application in urban context it is necessary to establish new biotechnology tools and test their efficacy in laboratory trials. The major aims of this work were (i) to isolate EcM species known to associate with the selected tree species chosen (Tilia tomentosa) and (ii) to develop and test (in situ & ex situ) a specific RT-qPCR assays for detection and quantification of ectomycorrhizal RNA. The latter will allow fast, quantitative monitoring of the selected target species over time, space or different environmental conditions and can be directly applied to RNA samples from in-vitro and field experiments. Method: Two key-criteria were used in the fungi species selection: EcM species that are present on healthy urban trees, but absent on the unhealthy ones; and (ii) EcM species from forest/old park trees that are not found on the unhealthy street trees. Fungi were isolated from Northern Portugal and identified by molecular techniques (DNA extraction, PCR, sequencing). For each fungal species selected, a real-time reverse-transcription quantitative PCR (RT-qPCR) assay was developed based on the ITS sequences available in NCBI and UNITED data base enabling specific monitoring and quantification of viable or active EcM of interest during the experiments that will be conducted. Results & Conclusions: Ten new fungal isolates were successfully isolated, comprising the genera Russula, Pisolithus and Paxillus. The standard curves obtained for mycelial quantification of the chosen EcM species satisfy the requirements for real-time PCR, showing high reaction efficiency. Under the conditions established in the present work, mycelium concentration was detectable to levels adequate for biomass in situ quantification.
- Ectomycorrhizal fungi help the establishment of Quercus suber plantations under abiotic stress conditionsPublication . Serafim, Cindy; Ramos, Miguel; Egas, Conceição; Améglio, Thierry; Castro, Paula
- Intraspecific variation of anatomical and chemical defensive traits in Maritime pine (Pinus pinaster) as factors in susceptibility to the pinewood nematode (Bursaphelenchus xylophilus)Publication . Zas, Rafael; Moreira, Xoaquín; Ramos, Miguel; Lima, Marta R. M.; Silva, Marta Nunes da; Solla, Alejandro; Vasconcelos, Marta; Sampedro, LuisKey message Migration ability of the PWN through wood branch tissues of adult Maritime pine trees significantly differed among Iberian provenances and this variation was related to differences in anatomical and chemical defensive traits. Abstract The pinewood nematode or pine wilt nematode (PWN; Bursaphelenchus xylophilus) is one of the most dangerous threats to European coniferous forests, especially for the susceptible Maritime pine (Pinus pinaster), a valuable forest resource in South Western Europe. The PWN is vectored by beetles of the genus Monochamus (Coleoptera, Cerambycidae) and once inoculated in healthy branches, it quickly migrates downward to the main trunk through the resin canal system. Therefore, the anatomy of the resin canal system may modulate its migration and proliferation rates. Using material from nine Maritime pine Iberian provenances established in a common garden trial, we investigated whether these provenances differed in their (1) resin canal anatomy, (2) concentration of chemical defences (non-volatile resin and total polyphenolics) in stems and (3) ability of the PWN to migrate through the pine woody tissues in ‘in vitro’ bioassays. Whether variation in anatomical and chemical defensive traits relates to differences in PWN migration across populations was also investigated. Significant intraspecific variation in anatomical and chemical defensive traits and in nematode migration rates through pine tissues was observed. Moreover, the variation in nematode migration rate among pine provenances was related to differences in both anatomical and chemical features. Overall, this study highlights the role of plant genetics in the development of defensive traits against this harmful coniferous pest. The observed intraspecific variation should be taken into account when considering breeding as a strategy to provide areas of high risk of PWN with resistant genetic material.
- Mycopigments for a sustainable textile industryPublication . Ramos, Miguel; Paulo, Ana; Castro, PaulaThe textile industry represents a very important economic sector is several countries, being also associated to a high environmental impact, caused by the production and use of hazardous compounds and synthetic dyes. Therefore, the demand for natural, harmless as well as sustainable dyes and pigments has been increasing tremendously across the world. Mycopigments are produced by fungi and have emerged worldwide as promising alternatives to synthetic pigments due to their higher safety level and wide range of applications. The extraction of mycopigments from macrofungi such as Pisolithus tinctorius has been performed since ancient times, but its use for fabric dyeing is mostly reduced to artisanal initiatives. These fungi are normally obtained from nature, under variable growth conditions and with an unpredictable availability. To increase the amount of these natural pigments in the market it is necessary to grow fungi and to extract the mycopigments under optimized and controlled conditions, possible to reproduce at industrial settings. The main objective of our work was to compare the characteristics of mycopigments obtained from Pisolithus tinctorius grown in nature and under laboratorial conditions, and to understand how controlled growth conditions can be influence the mycopigments production. Main results indicate that the growth conditions can affect the type of pigments that are produced, consequently affecting the physical-chemical interaction of the pigments with the natural fibers used in the textile industry. Our future goal is to be able to produce mycopigments in bioreactors and to obtain value from the exceeding mycelia. For the case of Pisolithus tinctorius, commonly used as soil fertilizer, the mycelia can be used for increasing the survival rate of trees produced in nurseries, after transplantation. To invest in mycopigments production can represent a giant step towards an increased sustainability of the textile sector, while creating a new market opportunity.
- Non-invasive monitoring of stress response of urban trees inoculated with EcMPublication . Serafim, Cindy; Ramos, Miguel; Yilmaz, Tugce; Sousa, Nadine; Castro, Paula M. L.
- Performance of Quercus suber L. at nursery stage - application of two bio-inoculants under two distinct environmentsPublication . Araújo, Giovânia C.; Sousa, Nadine; Ramos, Miguel; Vega, Alberto L.; Castro, Paula M. L.Key message - Despite the fact that the technique of application of bioinoculants improved the quality of Quercus suber L. seedlings produced in nurseries, these benefits are dependent on the ecological conditions of the site and the composition of the applied inoculum, which interferes with the profile of the local fungal community. Context - Quercus suber L. plays a key ecological and socio-economical role in the Iberian Peninsula. Symbiotic ectomycorrhizal fungi-ECM are crucial partners of several tree species, and assessing the efficacy of bioinoculants at nursery stage helps devising tools to increase plant resilience. Aims - The aim of this study was to compare the effects of two inocula formulations of mixed ECM fungi and bacteria on the quality of seedlings produced in two forest nurseries, differing in environmental conditions and forest embedment. Methods - Quercus suber L. seedlings were inoculated with a commercial product containing Pisolithus tinctorius (Pers) Coker Couch - Scleroderma sp., and six bacterial species and with a non-commercial fungal and bacterial dual inoculum (Suillus granulatus (L.) Roussel + Mesorhizobium sp.). Biometric and nutritional parameters and morphological quality indexes were determined on seedlings. The ECMcommunity was assessed by denaturing gradient gel electrophoresis and cloning-sequencing. Results - In both nurseries, the seedling quality index in inoculated was up to 2-fold higher than in non-inoculated seedlings. Plant biomass differed significantly among nurseries. The inoculum influenced the profile of the fungal community. S. granulatus and P. tinctorius persisted for 6 months in the inoculated seedlings. Conclusion- The nursery ecosystem influenced plant growth. Inoculation treatments increased plant performance; however, the dual inoculum resulted in more consistent improvements of Q. suber at nursery stage, highlighting the importance of inocula selection.
- Potential of persistent ectomycorrhizal fungi in fire impacted soil to degrade fluorinated pollutantsPublication . Franco, Albina; Sousa, Nadine R.; Ramos, Miguel; Oliveira, Rui S.; Castro, P. M. L.
- Selection and acclimatization of strains of edible mycorrhizal fungi for improved field persistencePublication . Ramos, Miguel; Sousa, Nadine; Castro, Paula M. L.
- Soil organic matter rather than ectomycorrhizal diversity is related to urban tree healthPublication . Geel, Maarten Van; Yu, Kang; Peeters, Gerrit; van Acker, Kasper; Ramos, Miguel; Serafim, Cindy; Kastendeuch, Pierre; Najjar, Georges; Ameglio, Thierry; Ngao, Jérôme; Saudreau, Marc; Castro, Paula; Somers, Ben; Honnay, OlivierUrban trees provide many ecosystem services, including carbon sequestration, air quality improvement, storm water attenuation and energy conservation, to people living in cities. Provisioning of ecosystem services by urban trees, however, may be jeopardized by the typically poor quality of the soils in urban areas. Given their well-known multifunctional role in forest ecosystems, ectomycorrhizal fungi (EcM) may also contribute to urban tree health and thus ecosystem service provisioning. Yet, no studies so far have directly related in situ EcM community composition to urban tree health indicators. Here, two previously collected datasets were combined: i) tree health data of 175 Tilia tomentosa trees from three European cities (Leuven, Strasbourg and Porto) estimated using a range of reflectance, chlorophyll fluorescence and physical leaf indicators, and ii) ectomycorrhizal diversity of these trees as characterized by next-generation sequencing. Tree health indicators were related to soil characteristics and EcM diversity using canonical redundancy analysis. Soil organic matter significantly explained variation in tree health indicators whereas no significant relation between mycorrhizal diversity variables and the tree health indicators was found. We conclude that mainly soil organic matter, through promoting soil aggregate formation and porosity, and thus indirectly tree water availability, positively affects the health of trees in urban areas. Our results suggest that urban planners should not overlook the importance of soil quality and its water holding capacity for the health of urban trees and potentially also for the ecosystem services they deliver. Further research should also study other soil microbiota which may independently, or in interaction with ectomycorrhiza, mediate tree performance in urban settings.