Infection with the fungal endophyte Epichloë festucae may alter the allelopathic potential of red fescue

16 páginas, 3 tablas, 2 figurasRed fescue (Festuca rubra) is a perennial grass used as both forage and turfgrass. Asymptomatic plants of this species are systemically infected by the fungal endophyte Epichloë festucae, which has a beneficial effect on the infected plants. The aim of this study was to determine the effect of the endophyte Epichloë festucae on the allelopathic potential of Festuca rubra against four associated pasture species that are also considered as weeds in lawns, Trifolium pratense, Trifolium repens, Lotus corniculatus, and Plantago lanceolata. Two experiments were designed to evaluate the allelopathic effect of extracts from the roots and leaves of endophyte-infected (E+) and non-infected (E-) plants on the germination and seedling growth of the four target species. Regardless of the endophyte status of the host plant, leaf extracts elicited a stronger reduction in germination and seedling growth than root extracts. Extracts from E+ plants reduced the speed of germination index of Trifolium spp. to a greater extent than those from E- plants. Radicle length of the target species was the parameter most affected by the presence of the endophyte in F. rubra. Root extracts from E+ plants had a greater inhibitory effect on the radicle growth of the target species than did root extracts from E- plants. A greater concentration in total phenolic compounds was found in the roots of E+ plants than of E-; however, this difference was not observed in the leaves. Thus, the allelopathic potential of F. rubra is altered in infected plants.This work was funded by project AGL2008-01159AGR from the Spanish Ministry of Science and Innovation and FEDER. Thanks are due to Dr. Nuria Pedrol for helpful comments in the experimental design and procedures and to Dr. Iñigo Zabalgogeazcoa for comments that improved the manuscript.Peer reviewe

Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption

Caracterización de un virus que infecta al hongo Endofítico Epichloë festucae

[ES] Epichloë festucae (Ascomycota) infecta a la gramínea Festuca rubra. La infección a en gramíneas confiere a la planta una serie de beneficios, entre otros ser más resistentes a herbívoros. E. festucae está infectado a su vez por un genoma vírico de 5109bp RNAbc, dicho genoma fue secuenciado, y adicionalmente se estudió su incidencia en poblaciones naturales, al igual que su modo de transmisión. En función a las características que presenta el genoma viral, se ha caracterizado como miembro de la familia Totiviridae. Está formado por dos ORFs que están solapados por un tetranucleótido; el ORF1 codifica para una posible proteína de la cápsida con una longitud de 765 aminoácidos; por su parte el ORF2 (en desfase de lectura de -1 con respecto al ORF1, codifica para una posible proteína RNA polimerasa RNA dependiente de una longitud de 826 aminoácidos. Este virus es denominado Epichloë festucae virus 1 (EfV1), y está relacionado con los miembros del género Victorivirus que infecta a hongos filamentosos, y que es deducido por medio de un análisis filogenético de la CPs y la RdRps. En dos poblaciones naturales de Epichloë festucae, el 36.4% de los aislados están infectados por EfV1. El virus fue transmitido por esporas asexuales (conidios) con una eficiencia del 100%, mientras que no se produce nunca transmisión por ascosporas procedentes del cruce sexual entre individuos con virus y sin virus.[EN] Festucae Epichloë (Ascomycota) infects the grass Festuca rubra. The infection of grasses gives the plant a number of benefits, including more resistant to herbivores. E. festucae turn is infected by a RNAbc 5109bp viral genome, this genome was sequenced, and further studied its effect on natural populations, as well as their mode of transmission. According to the features found in the viral genome has been characterized as Totiviridae family member. It consists of two ORFs which are overlapping by a tetranucleotide, the ORF1 coding for a possible coat protein with a length of 765 amino acids, for its part, the ORF2 (in reading lag of -1 with respect to ORF1, encodes a possible RNA-dependent RNA polymerase protein of 826 amino acids long. This virus is called Epichloë festucae virus 1 (EfV1), and is related to members of the genus Victorivirus infecting filamentous fungi, and is inferred by a phylogenetic analysis of the CPs and RdRps. Two natural populations of Epichloë festucae, 36.4% of isolates are infected EfV1. The virus was transmitted through asexual spores (conidia) with an efficiency of 100%, while transmission never occurs by sexual ascospores from the cross between individuals with and without virus virus

Infection with the fungal endophyte Epichloë festucae may alter the allelopathic potential of red fescue

16 páginas, 3 tablas, 2 figurasRed fescue (Festuca rubra) is a perennial grass used as both forage and turfgrass. Asymptomatic plants of this species are systemically infected by the fungal endophyte Epichloë festucae, which has a beneficial effect on the infected plants. The aim of this study was to determine the effect of the endophyte Epichloë festucae on the allelopathic potential of Festuca rubra against four associated pasture species that are also considered as weeds in lawns, Trifolium pratense, Trifolium repens, Lotus corniculatus, and Plantago lanceolata. Two experiments were designed to evaluate the allelopathic effect of extracts from the roots and leaves of endophyte-infected (E+) and non-infected (E-) plants on the germination and seedling growth of the four target species. Regardless of the endophyte status of the host plant, leaf extracts elicited a stronger reduction in germination and seedling growth than root extracts. Extracts from E+ plants reduced the speed of germination index of Trifolium spp. to a greater extent than those from E- plants. Radicle length of the target species was the parameter most affected by the presence of the endophyte in F. rubra. Root extracts from E+ plants had a greater inhibitory effect on the radicle growth of the target species than did root extracts from E- plants. A greater concentration in total phenolic compounds was found in the roots of E+ plants than of E-; however, this difference was not observed in the leaves. Thus, the allelopathic potential of F. rubra is altered in infected plants.This work was funded by project AGL2008-01159AGR from the Spanish Ministry of Science and Innovation and FEDER. Thanks are due to Dr. Nuria Pedrol for helpful comments in the experimental design and procedures and to Dr. Iñigo Zabalgogeazcoa for comments that improved the manuscript.Peer reviewe

Estudio de la infección vírica presente en el hongo endofitico Epichloë festuca en poblaciones naturales de Festuca rubra

5 páginas, 2 figuras. -- Trabajo generado en XLIV Reunión Científica de la SEEP en Salamanca[EN]The presence of mycoviruses in natural populations of the endophytic fungus Epichloë festucae has been analyzed in asymptomatic plants of Festuca rubra, in pasture lands. These infections represent a problem in animal grazing pastures. In these ecosystems, which are considered a center of genetic diversity of Festuca rubra, it has been found that up to 70% of plants were infected by the endophyte E. Festucae. On the other hand, it has been investigated the existence of two viruses: Efv-1 and Efv-2, their frequency of appearance, and the way they are transmitted in native populations of E. festucae. This has allowed to discover the presence of different lineages in a population of E. festucae, where the presence of micoviruses had been detected. The advantages the plant may get with the endophytic infection, together with the benefits the virus may give to the endophyte have got enough interest to achieve an investigation with a view to using the relation virus-endophyte-plant intending to improve grass.[ES]En este trabajo se ha estudiado la presencia de micovirus en poblaciones naturales del hongo endofítico Epichloë festucae, en plantas asintomáticas de Festuca rubra en pastos de dehesa. Las plantas que están infectadas por endofitos contienen alcaloides que son tóxicos para herbívoros, lo que puede representar un problema en los pastos destinados al consumo animal. En estos ecosistemas, considerados como centro de diversidad genética de Festuca rubra, se ha encontrado que hasta el 70% de estas plantas estan infestadas por E. festucae. También se ha analizado la presencia de dos virus Efv-1 y Efv-2, la frecuencia con la que aparecen y la manera en que se transmiten dentro de las poblaciones naturales de E. festucae. Esto ha permitido detectar la presencia de diferentes linajes dentro de una misma población de E. festucae, determinándose además la presencia de micovirus. Los beneficios que la planta consigue con la infección endofítica, junto con el que el virus puede proporcionar al endofito, generan suficiente interés para realizar estudios que permitan conocer la relación virus-endofito-planta.Este trabajo ha sido financiado por el MCYTT proyecto AGL2002-02766Peer reviewe

Effects of fungal endophyte infection in the grass Festuca rubra on germination and growth of four legume species.

Red fescue (Festuca rubra) is a perennial grass present in a wide range of ecological conditions. It is also included in mixtures with other grasses and legumes for several purposes. The objective of this paper was to determine the effect of Festuca rubra plants, infected and non-infected by the endophyte Epichloë festucae, on the germination and seedling growth of four legume species. During three weeks, a greenhouse experiment was carried out with infected and non-infected plants of F. rubra, and four legume species: Trifolium pratense, Trifolium repens, Trifolium subterraneum and Lotus corniculatus. The emergence of the legumes was not affected by the presence of F. rubra plants. However, the length and biomass production of the four legumes was reduced in the presence of F. rubra plants. The decrease in shoot length was greater than that in root length. There was a significant effect of endophyte infection status of F. rubra plants on the root length and root biomass of legumes. The reduction in root length and root dry weight of legume seedlings was greater in the presence of infected plants than in the presence of non-infected plants.This research was founded by AGL2008-01159AGR project, from the Spanish Ministry of Science and Technology and FEDER.Peer reviewe

ldentification of endophyticl fungí ín natural populations of Lolium perenne.

XLIV Reunión Científica de la Sociedad Española para el Estudio de los Pastos. 10-14 de mayo de 2004, Salamanca (España){ESP} Se han identificado diversas especies de hongos endofíticos que infectan a Lo/ium perenne, en los pastos de las provincias de Salamanca, Zamora y León. La incidencia media de infección fue de 55,01 %. En función de su morfología se identificaron tres tipos de endofitos: Tipo A con un crecimiento lento y sin conidios; Tipo B de crecimiento rápido y sin conidios; Tipo C con crecimiento rápido y con conidios. Su identificación molecular fue realizada por medio de secuencias nucleotídicas pertenecientes a la región ITS-l/5.8 S rRNA/lTS2; la secuenciación de las distintas muestras permitieron su agrupación en: Neotyphodium sp., Epich/oe festucae yEpichloe typhina. Finalmente, en plantas de Lolium perenne se detectó ergovalina, compuesto relacionado con el síndrome de festucosis en ganado vacuno, presente en una concentración que oscila entre 0,05 y 3,90 mg gol.{ENG} Endophyte fungí that infect Lolium perenne in the provinces of Salamanca, Zamora and León were identified. Average infection incidence by endophyte was 55.01 %. Based on their morphology three grups of endophytes were identified. Type A slow growth without conidias; type B fast growth without conidiasj type C fast growth with conidias. Molecular indentification was done using secuences from ITS-l/r RNA/ ITS2 regian, secuences samples were grouped within: Neotyphodium sp., Epichloe festucae andEptch/oe typhina. Finally, ergovaline was detected on sampes of Lolium perenne, in 0.05 to 3.90 mg concentration. Ergovaline i8 related to festucosü~ syndrome in cattle.Este trabajo ha sido financiado por el proyecto de la Junta de Castilla y León (CS! 6/01)

A Rosemary Extract Rich in Carnosic Acid Selectively Modulates Caecum Microbiota and Inhibits β-Glucosidase Activity, Altering Fiber and Short Chain Fatty Acids Fecal Excretion in Lean and Obese Female Rats

[Background] Carnosic acid (CA) and rosemary extracts (RE) show body-weight, energy metabolism and inflammation regulatory properties in animal models but the mechanisms are not yet understood. Gut microbiota plays an important role in the host metabolism and inflammatory status and is modulated by the diet. The aim of this research was to investigate whether a RE enriched in CA affected caecum microbiota composition and activity in a rat model of genetic obesity.[Methods and Principal Findings] A RE (40% CA) was administered with the diet (0.5% w/w) to lean (fa/+) and obese (fa/fa) female Zucker rats for 64 days. Changes in the microbiota composition and β-glucosidase activity in the caecum and in the levels of macronutrients and short chain fatty acids (SCFA) in feces were examined. The RE increased the Blautia coccoides and Bacteroides/Prevotella groups and reduced the Lactobacillus/Leuconostoc/Pediococccus group in both types of animals. Clostridium leptum was significantly decreased and Bifidobacterium increased only in the lean rats. β-Glucosidase activity was significantly reduced and fecal fiber excretion increased in the two genotypes. The RE also increased the main SCFA excreted in the feces of the obese rats but decreased them in the lean rats reflecting important differences in the uptake and metabolism of these molecules between the two genotypes.[Conclusions] Our results indicate that the consumption of a RE enriched in CA modifies microbiota composition and decreases β-glucosidase activity in the caecum of female Zucker rats while it increases fiber fecal elimination. These results may contribute to explain the body weight gain reducing effects of the RE. The mutated leptin receptor of the obese animals significantly affects the microbiota composition, the SCFA fecal excretion and the host response to the RE intake.This project was financed by the Spanish Centre for the Development of Industrial Technology (CDTI) as part of the project SENIFOOD, which belongs to the CENIT subvention program (Ref: CEN-20091006). This work was also supported by the Project Consolider Ingenio 2010, CSD2007-00063 (Fun-C-Food) and by the Seneca Foundation of the Region of Murcia, Spain (Group of Excellence GERM 06 04486 and 05556/PI/04).Peer reviewe

Effect of the fungal endophyte Epichloë festucae on the allelopathic potential of Festuca rubra grass

Resumen del trabajo presentado en el 5th World Congress on Allelopathy, celebrado en Saratoga Springs, New York (Estados Unidos), del 21 al 25 de septiembre de 2008In Mediterranean grasslands from the ‘dehesa’ ecosystem (Spain), a 70% of Festuca rubra plants are systemically and asymptomatically infected by the fungal endophyte Epichloë festucae. Endophyte-infected grasses are characterized by increased resistance to herbivores and abiotic stresses, as compared to non-infected grasses. The objective of this work was to determine whether allelopathic potential of Festuca rubra is affected by the presence of the fungal endophyte Epichloë festucae. For this purpose, experiments in Petri dishes were carried out to evaluate the effect of extracts from infected (E+) and noninfected (E-) Festuca rubra plants on the germination and seedling growth of several legume species: Trifolium pratense, T. repens, T. subterraneum, Anthyllis vulneraria and Lotus corniculatus. Leaf and root plant tissues were used to prepare aqueous extracts. All extracts inhibited radicle growth over control and extracts of leaves caused more inhibition than root extracts. The effects of root extracts of E+ plants on the radicle growth of T. repens and T. pratense were more pronounced than extracts of E- plants. Thus, the percentage of radicle inhibition (over control) of T. repens was 45% with E+ and 29% with E- root extracts, and that of T. pratense was 50% with E+ and 0% with E- extracts. The effect in Anthyllis vulneraria was the opposite and root extracts of E- plants inhibited radicle growth in a greater extent than E+ extracts. The effect of the endophyte in T. subterraneum and Lotus corniculatus was not significant. The effect of F. rubra extracts on germination was lower. Only concentrate leaf extract decreased percentage of germination over control, and it was independent of fungus. We found a greater content of total phenolics in extracts of roots of E+ plants than in those of E- plants. These results suggest that fungal endophyte can affect allelopathic potential of F. rubra plants

EFFECT OF FESTUCA RUBRA FUNGAL ENDOPHYTE ON GERMINATION AND GROWTH OF GRASSLAND SPECIES

Trabajo presentado en la XLVIII Reunión Científica de la SEEP, celebrada en Huesca (España), del 15 al 18 de junio de 2009[ESP]Varias especies vegetales producen sustancias químicas que inhiben el crecimiento de otras especies. Este tipo de interacciones se denominan alelopáticas y tienen gran interés por su aplicación como herbicidas naturales. El objetivo de este trabajo fue determinar el efecto que produce el hongo endofítico Epichloë festucae en el potencial alelopático de Festuca rubra, una gramínea muy apreciada en céspedes. En una serie de bioensayos en placas Petri y en macetas se evaluó la actividad alelopática tanto de extractos como de la misma planta de F. rubra, en versión infectada (E+) y no infectada (E-), sobre la germinación y el crecimiento de las especies Trifolium repens, Trifolium pratense y Plantago lanceolata. Los resultados mostraron que los extractos de raíces de F. rubra E+ inhiben el crecimiento de radícula de T. pratense y P. lanceolata. Además, en los ensayos realizados en macetas, en presencia de plantas E+ la longitud y el peso de radícula de las tres especies fue menor que en presencia de plantas E-. Estos resultados sugieren que la presencia de E. festucae puede incrementar el potencial alelopático de las raíces de F. rubra sobre estas especies. [ENG] Several plant species produce chemicals altering plant growth and development. This kind of chemical interaction between plants are known as allelopathic interactions and are of interest because of their properties as natural herbicides. The objective of this study was to determine the effect of the fungal endophyte Epichloë festucae on the allelopathic potential of Festuca rubra. Several bioassays were carried out in Petri plates and in pots in order to evaluate the effect of F. rubra plants (infected and non infected) and their extracts on the germination and seedling growth of Trifolium repens, Trifolium pratense and Plantago lanceolata. The results show that root extracts from infected F. rubra inhibited radicle growth of T. pratense and P. lanceolata. Furthermore, the radicle length and radicle weight of the three species was lower when growing with infected plants than with non-infected plants. These results suggest that the presence of E. festucae may increase the allelopathic potential of F. rubra roots on other grassland species, mainly due to the root activity.Este trabajo ha sido financiado por el Ministerio de Educación y Ciencia, Proyecto AGL 2005-02839/AGR y fondos FEDER.Peer reviewe