Search results for " endophyte"
showing 10 items of 26 documents
Identification of Acremonium isolates from grapevines and evaluation of their antagonism towards Plasmopara viticola
2015
Some endophytic fungal genera in Vitis vinifera, including Acremonium, have been reported as antagonists of Plasmopara viticola. Endophytic Acremonium isolates from an asymptomatic grapevine cultivar Inzolia from Italy were identified by morphological features and multigene phylogenies of ITS, 18S and 28S genes, and their intra-specific genomic diversity was analyzed by RAPD analysis. Culture filtrates (CFs) obtained from Acremonium isolates were tested in vitro for their inhibitory activity against the P. viticola sporangia germination. Among 94 isolates, 68 belonged to the Acremonium persicinum and 26 to the Acremonium sclerotigenum. RAPD analysis grouped the A. persicinum isolates into 1…
Plant growth promoting potential of bacterial endophytes from three terrestrial mediterranean orchid species
2020
Orchids are highly dependent on symbiotic microorganisms during their entire life cycle. Whereas an important role in orchid seed germination and early plant development is well established for mycorrhizal fungi, the influence of endophytic bacteria on orchid growth has been less investigated. Here, we report the isolation of endophytic bacteria from different organs of three terrestrial Mediterranean orchid species (Spiranthes spiralis, Serapias vomeracea and Neottia ovata), the investigation of their potential Plant Growth-Promoting (PGP) traits and their interaction with the orchid mycorrhizal (OM) fungus Tulasnella calospora in vitro. Little overlap was found among endophytic bacteria i…
Endophytic Bacteria and Essential Oil from Origanum vulgare ssp. vulgare Share Some VOCs with an Antibacterial Activity
2022
Medicinal aromatic plants’ essential oils (EOs) are mixtures of volatile compounds showing antimicrobial activity, which could be exploited to face the emerging problem of multi-drug resistance. Their chemical composition can depend on the interactions between the plant and its endophytic microbiota, which is known to synthesize volatile organic compounds (VOCs). However, it is still not clear whether those volatile metabolites can contribute to the composition of the aroma profile of plants’ EOs. The aims of this study were to characterize medicinal plant O. vulgare ssp. vulgare bacterial endophyte VOCs, evaluating their ability to antagonize the growth of opportunistic human pathogens bel…
Endophytic Bacteria Associated with Origanum heracleoticum L. (Lamiaceae) Seeds
2022
Seed-associated microbiota are believed to play a crucial role in seed germination, seedling establishment, and plant growth and fitness stimulation, due to the vertical transmission of a core microbiota from seeds to the next generations. It might be hypothesized that medicinal and aromatic plants could use the seeds as vectors to vertically transfer beneficial endophytes, providing plants with metabolic pathways that could influence phytochemicals production. Here, we investigated the localization, the structure and the composition of the bacterial endophytic population that resides in Origanum heracleoticum L. seeds. Endocellular bacteria, surrounded by a wall, were localized close to th…
Genomic Analysis of Endophytic Bacillus-Related Strains Isolated from the Medicinal Plant Origanum vulgare L. Revealed the Presence of Metabolic Path…
2022
Multidrug-resistant pathogens represent a serious threat to human health. The inefficacy of traditional antibiotic drugs could be surmounted through the exploitation of natural bioactive compounds of which medicinal plants are a great reservoir. The finding that bacteria living inside plant tissues, (i.e., the endophytic bacterial microbiome) can influence the synthesis of the aforementioned compounds leads to the necessity of unraveling the mechanisms involved in the determination of this symbiotic relationship. Here, we report the genome sequence of four endophytic bacterial strains isolated from the medicinal plant Origanum vulgare L. and able to antagonize the growth of opportunistic pa…
Apulian olive sapwood endophytes to cope with Xylella fastidiosa: community analysis, antagonists screening, colonization efficiency, and genes expre…
2021
This dissertation comprises a series of studies aimed at exploring the cultivable endophytic communities indigenous to the sapwood of Apulian olive cultivars, identifying potential antagonists against Xylella fastidiosa, pauca ST53, and demonstrating their colonization efficiency and associated effects on olive defence-related genes. This work starts with an extensive analysis of cultivable sapwood endophytes from resistant and susceptible cultivars distributed across phytosanitary zones in Apulia. After multiple isolation of endophyte colonies, the results were translated into quantitative indicators. It was found that the resistant cultivar 'Leccino' showed high stability and diversity of…
Lulwoana sp., a dark septate endophyte (DSE) in roots of Posidonia oceanica (L.) Delile seagrass
2014
Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anch…
Detection of Bacterial Endophytes in Vitis vinifera L. and Antibiotic Activity against Grapevine Fungal Pathogens
2016
This chapter presents the results of studies conducted to (i) detect and localize endophytic bacteria in symptomless and symptomatic leaf tissues of grapevine (Vitis vinifera) using fluorescence in situ hybridization (FISH) in combination with confocal laser scanning microscopy (CLSM); and (ii) test the antagonistic activity of Bacillus amyloliquefaciens AG1, previously isolated from grape wood affected by the esca syndrome, against grapevine fungal pathogens: Alternaria alternata, obtained from grapevine leaves showing necrotic concentric spots; Aspergillus carbonarius, A. ochraceus and Penicillium verrucosum, isolated from grapes affected by secondary rot; Botrytis cinerea, isolated from …
Cultivable Fungal Endophytes in Roots, Rhizomes and Leaves of Posidonia oceanica (L.) Delile along the Coast of Sicily, Italy
2022
The presence of endophytic fungi in the roots, rhizomes, and leaves of Posidonia oceanica was evaluated in different localities of the Sicilian coast. Samples of roots, rhizomes, and leaves were submitted to isolation techniques, and the obtained fungal colonies were identified by morphological and molecular (rRNA sequencing) analysis. Fungal endophytes occurred mainly in roots and occasionally in rhizomes and leaves. Lulwoana sp. was the most frequent of the isolated taxa, suggesting a strong interaction with the host. In addition, eight other fungal taxa were isolated. In particular, fungi of the genus Ochroconis and family Xylariaceae were identified as endophytes in healthy plants at al…
Identification et caractérisation de candidats d'origine naturelle à action herbicide pour contrôler les adventices
2016
Les produits phytopharmaceutiques (ou pesticides) utilisés aujourd'hui en agriculture sont pointés du doigt pour leurs impacts potentiels sur l’environnement et les écosystèmes et pour les risques qu’ils sont susceptibles d’engendrer pour la santé animale et humaine (Inserm, 2013). Les objectifs majeurs de la thèse sont d’isoler et identifier des microorganismes pathogènes des adventices, et d’acquérir des connaissances sur les mécanismes de l'interaction plante adventicemicroorganismes dans le cadre du développement de bioherbicides pour contrôler les adventices. Outre une analyse bibliographique sur l'état des connaissances relatif aux interactions adventicesmicroorganismes, le travail de…