AUTHOR=Pereira Eric C. , Vazquez de Aldana Beatriz R. , Arellano Juan B. , Zabalgogeazcoa Iñigo 

TITLE=The Role of Fungal Microbiome Components on the Adaptation to Salinity of Festuca rubra subsp. pruinosa

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.695717

DOI=10.3389/fpls.2021.695717

ISSN=1664-462X

ABSTRACT=<p><italic>Festuca rubra</italic> subsp. <italic>pruinosa</italic> 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 <italic>Epichloë festucae</italic> in aboveground tissues and with <italic>Fusarium oxysporum</italic> and <italic>Periconia macrospinosa</italic> in roots. In this study, we hypothesized that these fungi could affect the performance of <italic>F. rubra</italic> plants under salinity, being important complements for plant habitat adaptation. Two lines of <italic>F. rubra</italic>, each one consisting of <italic>Epichloë</italic>-infected and <italic>Epichloë</italic>-free clones, were inoculated with the root endophytes (<italic>F. oxysporum</italic> and <italic>P. macrospinosa</italic>) and subjected to a salinity treatment. Under salinity, plants symbiotic with <italic>Epichloë</italic> had lower Na<sup>+</sup> content than non-symbiotic plants, but this effect was not translated into plant growth. <italic>P. macrospinosa</italic> promoted leaf and root growth in the presence and absence of salinity, and <italic>F. oxysporum</italic> promoted leaf and root growth in the presence and absence of salinity, plus a decrease in leaf Na<sup>+</sup> content under salinity. The growth responses could be due to functions related to improved nutrient acquisition, while the reduction of Na<sup>+</sup> content might be associated with salinity tolerance and plant survival in the long term. Each of these three components of the <italic>F. rubra</italic> 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 <italic>Epichloë</italic> itself in FRP salt tolerance, there is evidence that <italic>Epichloë</italic> can interact with root endophytes, affecting host plant performance.</p>