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15 páginas, 2 tablas, 6 figuras. - The final publication is available at www.springerlink.com ; Grasses represent one of the Earth's most common plant groups, and natural and cultivated habitats dominated by grasses cover about 40% of the land surface. In turn, each grass species hosts multiple fungal species which can behave as endophytes. An analysis of the endophytic taxa identified in surveys conducted in 14 grass species showed that some of the most frequent taxa on each grass were also present across several host grasses. These taxa were Alternaria, Epicoccum, Cladosporium, Fusarium, and a few others. A similar analysis of airborne fungi surveyed at 41 different locations throughout the world showed that some of the most geographically widespread, and most locally frequent airborne fungi belonged to the same genera that are dominant endophytes in grasses (i.e. Cladosporium, Alternaria, Fusarium, etc.). Therefore, airborne spores of genera that are ubiquitous in grasses are common worldwide and attain high atmospheric concentrations. In addition, spores of the above mentioned fungi are also important respiratory allergens. Direct observation indicates that saprobic colonization and sporulation of non-systemic grass endophytes could become unrestrained when their host plant tissue dies. Subsequently, when appropriate environmental conditions favour sporulation on grass host surfaces, the natural cycle for airborne conidia initiates, and large numbers of these conidia disperse as inoculum for new endophytic infections. Therefore, the cycle of endophytism may be an important link between climate, plant biology and public health. ; This work was funded by Project AGL2011-22783, granted by the Spanish Government. We thank members of COST Action FA1103. ; Peer reviewed

15 páginas, 8 figuras, 1 tabla ; SpainFestuca rubra subsp. pruinosa is a perennial grass that inhabits sea cliffs, a habitat where salinity and low nutrient availability occur. These plants have a rich fungal microbiome, and particularly common are their associations with Epichloë festucae in aboveground tissues and with Fusarium oxysporum and Periconia macrospinosa in roots. In this study, we hypothesized that these fungi could affect the performance of F. rubra plants under salinity, being important complements for plant habitat adaptation. Two lines of F. rubra, each one consisting of Epichloë-infected and Epichloë-free clones, were inoculated with the root endophytes (F. oxysporum and P. macrospinosa) and subjected to a salinity treatment. Under salinity, plants symbiotic with Epichloë had lower Na+ content than non-symbiotic plants, but this effect was not translated into plant growth. P. macrospinosa promoted leaf and root growth in the presence and absence of salinity, and F. oxysporum promoted leaf and root growth in the presence and absence of salinity, plus a decrease in leaf Na+ content under salinity. The growth responses could be due to functions related to improved nutrient acquisition, while the reduction of Na+ content might be associated with salinity tolerance and plant survival in the long term. Each of these three components of the F. rubra core mycobiome contributed with different functions, which are beneficial and complementary for plant adaptation to its habitat in sea cliffs. Although our results do not support an obvious role of Epichloë itself in FRP salt tolerance, there is evidence that Epichloë can interact with root endophytes, affecting host plant performance ; This study has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 676480 and from the project "CLU-2019-05 – IRNASA/CSIC Unit of Excellence," funded by the Junta de Castilla y León and co-financed by the European Union (ERDF "Europe drives our growth"). ; Peer reviewed

14 páginas, 6 tablas, 7 figuras. -- The first publication by Frontiers Media is avalilable at https://www.frontiersin.org/articles/10.3389/fmicb.2018.03321/full ; Festuca rubra subsp. pruinosa is a perennial grass that inhabits sea cliffs of the Atlantic coasts of Europe. In this unhospitable environment plants grow in rock crevices and are exposed to abiotic stress factors such as low nutrient availability, wind, and salinity. Festuca rubra subsp. pruinosa is a host of the fungal endophyte Epichloë festucae, which colonizes aerial organs, but its root mycobiota is unknown. The culturable endophytic mycobiota of FRP roots was surveyed in a set of 105 plants sampled at five populations in marine cliffs from the northern coast of Spain. In total, 135 different fungal taxa were identified, 17 of them occurred in more than 10% of plants and in two or more populations. Seven taxa belonging to Fusarium, Diaporthe, Helotiales, Drechslera, Slopeiomyces, and Penicillium appeared to be constituents of the core microbiome of Festuca rubra subsp. pruinosa roots because they occurred in more than 20% of the plants analyzed, and at three or more populations. Most fungal strains analyzed (71.8%) were halotolerant. The presence of Epichloë festucae in aboveground tissue was detected in 65.7% of the plants, but its presence did not seem to significantly affect the structure of the core or other root microbiota, when compared to that of plants free of this endophyte. When plants of the grass Lolium perenne were inoculated with fungal strains obtained from Festuca rubra subsp. pruinosa roots, a Diaporthe strain significantly promoted leaf biomass production under normal and saline (200 mM NaCl) watering regimes. These results suggest that the core mycobiome of Festuca rubra subsp. pruinosa could have a role in host plant adaptation, and might be useful for the improvement of agricultural grasses. ; This study has received funding from the European Union's Horizon 2020 Research and Innovation Program under theMarie Skłodowska-Curie grant agreement no. 676480. LS was funded through a Talent Recruitment grant from "Obra Social La Caixa– Fundación CAN". We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Peer reviewed

9 páginas, 2 tablas, 2 figuras ; Plants host taxonomically and functionally complex communities of microbes. However, ecological studies on plant-microbe interactions rarely address the role of multiple co-occurring plant-associated microbes. Here, we contend that plant-associated microbes interact with each other and can have joint consequences for higher trophic levels. In this study we recorded the occurrence of the plant seed pathogenic fungus Claviceps purpurea and aphids (Sitobion sp.) on an established field experiment with red fescue (Festuca rubra) plants symbiotic to a seed transmitted endophytic fungus Epichloë festucae (E+) or non-symbiotic (E-). Both fungi are known to produce animal-toxic alkaloids. The study was conducted in a semi-natural setting, where E+ and E- plants from different origins (Spain and Northern Finland) were planted in a randomized design in a fenced common garden at Kevo Subarctic Research Station in Northern Finland. The results reveal that 45% of E+ plants were infected with Claviceps compared to 31% of E- plants. Uninfected plants had 4.5 times more aphids than Claviceps infected plants. By contrast, aphid infestation was unaffected by Epichloë symbiosis. Claviceps alkaloid concentrations correlated with a decrease in aphid numbers, which indicates their insect deterring features. These results show that plant mutualistic fungi can increase the infection probability of a pathogenic fungus, which then becomes beneficial to the plant by controlling herbivorous insects. Our study highlights the complexity and context dependency of species-species and multi-trophic interactions, thus challenging the labeling of species as plant mutualists or pathogens. ; This work was supported by the Academy of Finland (KS, Grant Nos. 295976 and 326226; MH, Grant No. 311077; BF, Grant No. 324523), the Spanish Ministry of Science and Innovation and FEDER grant PID2019-109133RB-I00, and from the project CLU-2019-05—IRNASA/CSIC Unit of Excellence funded by Junta de Castilla y León and cofinanced by the European Union (ERDF Europe drives our growth). ; Peer reviewed

From 1987 to 1996, nutritional quality of the main botanical components (grasses, legumes and forbs) in semi-arid grasslands in the dehesa ecosystem in western Spain was analysed. Herbage samples were collected at the end of spring season, in 30 locations, at two different topographic positions (upper and lower slope zones). Herbage mass over 2 cm and proportion of botanical components were estimated and samples were analysed for crude protein, neutral-detergent fibre (NDF), hemicellulose, cellulose, lignin and in vitro dry matter digestibility (DMD). Analysis of variance revealed a significant effect of sampling year on the herbage mass, proportion of botanical components and their nutritional quality. The three botanical groups followed similar year-to-year trends in their crude protein, cellulose and lignin contents and in vitro DMD. Herbage mass was not significantly related to any meteorological variables, suggesting that inter-annual variation in biomass production of botanically complex pastures cannot be explained by a single factor. However, annual precipitation was significantly related to the proportion of the botanical group which was dominant at each slope zone: grasses in the lower zone and forbs in the upper zone. In the upper zone spring precipitation explained part of the inter-annual variation in the NDF, cellulose, lignin contents and in vitro DMD of the botanical components. ; We are grateful to L. García, J.C. Estévez and M. Hernández for practical assistance. This work was financially supported by the Directorate General for Agriculture of the European Union (Contract 8001-CT90-0021) and the Spanish "Comisión Interministerial de Ciencia y Tecnología" (C.I.C.Y.T.; AGF96-0423). ; Peer reviewed

8 páginas, 1 figura, 3 tablas. -- Con la colaboración técnica de: L. García, J.C. Estevez, M. Hernández. -- This is an electronic version of an article published in Communications in Soil Science and Plant Analysis © 1996 Copyright Taylor & Francis; Communications in Soil Science and Plant Analysis is available online at: http://www.tandfonline.com/doi/abs/10.1080/00103629609369596 ; Ash content is a useful parameter in forage and grass quality studies, but the traditional methods used to quantify this parameter are tedious and sample processing time‐consumig is. Near infrared reflectance spectroscopy (MRS) overcomes some drawbacks of the traditional methods. Measurement of a sample's diffuse reflectance is rapid and non‐destructive and chemical reagents are not necessary, which is environmentally friendly. We predicted the ash content of herbage samples from semiarid grassland communities by NIRS. The samples were collected on different sites, over four consecutive years. The calibration equations generated from log 1/reflectance to predict ash content had a standard error of calibration (SEC) of 4.6 g kg‐1 and R2 of 0.88. The standard error of prediction (SEP) was 5.1 g kg‐1 and r was 0.94. ; This work was supported by the European Union (Contract N 8001-CT90-0021). ; Peer reviewed

19 páginas, 3 figuras, 4 tablas. -- Con la colaboración técnica de: M. Pelaez-Campoames de Labra, R. Villar Montero, L. García, J.C. Estevez y M. Hernández. -- This is an electronic version of an article published in Communications in Soil Science and Plant Analysis © 1995 Copyright Taylor & Francis; Communications in Soil Science and Plant Analysis is available online at: http://www.tandfonline.com/doi/abs/10.1080/00103629509369375 ; Botanical composition, aboveground biomass, protein, fibre content, and dry matter digestibility (DMD) were used as tools for studyinf the production and nutritional quality in semiarid grasslands. The study was carried out in herbaceous communities from Central-West of Spain over a period of five consecutive years (1986-1990). The grassland typologies were mainly related to their positions in topographical gradients (slopes) which characterize the regional landscape. The mean values for the production of aboveground biomass in the communities range between 126 and 304 g/m2 which seem fitted with the possibilites of those areas. The botanical composition is different in the two zones of the slope (upper and lower) and it responds to a defined pattern. Vegetation in the lower zones is dominated by grasses and in the upper zones by forbs. The correlation between production and botanical fractions considered (grasses, legumes and forbs) is significant for the grass group. The results show also that allocation of biomass among organic compounds is different in the three botanical groups. ; This work was supported by European Union Research Project (Contract No 800-CT90-0021) and a Grant of Programa Nacional de Formación de Personal Investigador en el Extranjero of Spanish government in the Department of Plant Ecology and Evolutionary Biology of Utrecht University ; Peer reviewed

14 páginas, 5 figuras, 3 tablas ; The widespread invasive success of Ulex europaeus, a thorny shrub native to NW Europe, remains to be understood from a functional perspective. According to the Enemy Release Hypothesis (ERH), lower pressure by vertebrate herbivores in the invaded areas should lead to lower investment in (costly) physical defenses, allowing plants to invest more in growth and/or reproduction. While U. europaeus seedlings have spines, adult plants have thorns, which are the main photosynthetic tissue (leaves are reduced to small phyllodes). Therefore, reduced biomass investment in thorns could compromise photosynthesis and growth in the invaded range. We hypothesized that U. europaeus plants in invaded ranges should show a reduction in the defensive components of thorns (e.g., softer and less fibrous tissues), but not reduced biomass allocation. We compared U. europaeus plants from the invaded (Chile) and native (Spain) distribution ranges regarding: (i) spinescence traits (thorn length, width, biomass, slenderness and bending strength) in adult plants, (ii) thorn fiber content and digestibility (proxies for palatability) in adult plants, and (iii) spine density in seedlings grown in a common garden. As expected, plants in the invaded range showed larger thorns, which contained less cellulose, were slenderer and easier to bend than those from plants in the native range. Likewise, seedlings from the invaded range showed lower spine density and more diameter growth, thus supporting the ERH. We found functional changes in spinescence traits between distribution ranges consistent with the dual role of thorns in U. europaeus, and these changes may partly explain its invasiveness. ; This work and SMV were funded by FONDECYT grant 3180289 (Chile). BRVA acknowledges funding from project ''CLU-2019-05 – IRNASA/CSIC Unit of Excellence'', funded by the Junta de Castilla y León and cofinanced by the European Union (ERDF ''Europe drives our growth''). AH was supported by the University of Alcala´'s Own Research Programme's 2019/20 Postdoctoral Grant, DARE research project (reference RTI 2018-096884-B-C32) financed by the Spanish Ministry of Science Innovation and Universities and Basque Country Government funding support to FisioClima CO2 (IT1022-16) research group. EPC acknowledge REMEDINAL3-CM S2013/MAE-2719 network (Comunidad de Madrid) and the funding of UCM Research Group Program (2018, 2020, Research group 91034. Plant Evolutionary Ecology and Restoration Ecology). EG acknowledges funding from FONDECYT grant 1180334. We thank Marina Briones Rizo and Antonio Requena Serrano for their help during sampling processing and Carlos Silva for his help with maps. We are greatful to the support of Red Fabáceas Invasoras en Iberoamérica (FFII): perspectiva alelopática e histoquímica (REDI170025, CONICYT, Chile). ; Peer reviewed

15 páginas, 5 figuras, 3 tablas ; Near infrared spectroscopy (NIRS) is an accurate, fast and nondestructive technique whose use in predicting forage quality has become increasingly relevant in recent decades. Epichloëinfected grass varieties are commonly used in areas with high pest pressure due to their better performances compared to endophyte-free varieties. The insect resistance of Epichloë-infected grasses has been associated with four main groups of endophyte secondary metabolites: ergot alkaloids, indole-diterpenes, lolines and peramine. Concentrations of these alkaloids are usually measured with high performance liquid chromatography or gas chromatography analysis, which are accurate methods but relatively expensive and laborious. In this paper, we developed a rapid method based on NIRS to detect and quantify loline alkaloids in wild accessions of Schedonorus pratensis infected with the fungal endophyte Epichloë uncinata. The quantitative NIR equations obtained by modified partial least squares algorithm had coefficients of correlation of 0.90, 0.78, 0.85, 0.90 for N-acetylloline, N-acetylnorloline and N-formylloline and the sum of the three, respectively. The acquired NIR spectra were also used for developing an equation to predict in planta fungal biomass with a coefficient of correlation of 0.75. These results showed that the use of NIRS and chemometrics allows the quantification of loline alkaloids and mycelial biomass in a heterogeneous set of endophyte-infected meadow fescue samples ; This study received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 676480. ; Peer reviewed