AUTHOR=Toghueo Rufin Marie Kouipou , Vázquez de Aldana Beatriz R. , Zabalgogeazcoa Iñigo 

TITLE=Diaporthe species associated with the maritime grass Festuca rubra subsp. pruinosa

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1105299

DOI=10.3389/fmicb.2023.1105299

ISSN=1664-302X

ABSTRACT=<p><italic>Festuca rubra</italic> subsp. <italic>pruinosa</italic> is a perennial grass growing in sea cliffs where plants are highly exposed to salinity and marine winds, and often grow in rock fissures where soil is absent. <italic>Diaporthe</italic> species are one of the most abundant components of the root microbiome of this grass and several <italic>Diaporthe</italic> isolates have been found to produce beneficial effects in their host and other plant species of agronomic importance. In this study, 22 strains of <italic>Diaporthe</italic> isolated as endophytes from roots of <italic>Festuca rubra</italic> subsp. <italic>pruinosa</italic> were characterized by molecular, morphological, and biochemical analyses. Sequences of the nuclear ribosomal internal transcribed spacers (ITS), translation elongation factor 1-α (<italic>TEF1</italic>), beta-tubulin (<italic>TUB</italic>), histone-3 (<italic>HIS</italic>), and calmodulin (<italic>CAL</italic>) genes were analyzed to identify the isolates. A multi-locus phylogenetic analysis of the combined five gene regions led to the identification of two new species named <italic>Diaporthe atlantica</italic> and <italic>Diaporthe iberica</italic>. <italic>Diaporthe atlantica</italic> is the most abundant <italic>Diaporthe</italic> species in its host plant, and <italic>Diaporthe iberica</italic> was also isolated from <italic>Celtica gigantea</italic>, another grass species growing in semiarid inland habitats. An <italic>in vitro</italic> biochemical characterization showed that all cultures of <italic>D. atlantica</italic> produced indole-3-acetic acid and ammonium, and the strains of <italic>D. iberica</italic> produced indole 3-acetic acid, ammonium, siderophores, and cellulase. <italic>Diaporthe atlantica is</italic> closely related to <italic>D. sclerotioides</italic>, a pathogen of cucurbits, and caused a growth reduction when inoculated in cucumber, melon, and watermelon.</p>