Abstract
Festuca 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.
Highlights
Festuca rubra is a perennial grass that occurs in very diverse ecological niches (Markgraf-Dannenberg, 1980; Inda et al, 2008)
The main purpose of this study was to explore the effect of the foliar endophyte E. festucae and the root endophytes F. oxysporum and P. macrospinosa on the performance of Festuca rubra subsp. pruinosa (FRP) plants subjected to salinity
FRP seems to rely on a tissue tolerance mechanism that allows its cells to accumulate Na+, possibly in vacuoles, and an osmotic counterbalance occurs in the cytoplasm by means of proline and K+
Summary
Festuca rubra is a perennial grass that occurs in very diverse ecological niches (Markgraf-Dannenberg, 1980; Inda et al, 2008). Within F. rubra, several subspecies have been defined and three of them, litoralis, pruinosa, and arenaria, occur in maritime habitats such as salt marshes, sea cliffs, or coastal sands. Pruinosa (FRP) inhabits sea cliffs of the Atlantic coasts of Europe (Figure 1; Markgraf-Dannenberg, 1980). This grass often grows as a chasmophyte in rock crevices with low nutrient availability and high exposure to seawater spray and desiccating winds. Some structural traits seemingly associated with salt tolerance in FRP are a dense layer of epicuticular wax which covers its leaves, stomata enclosed on the adaxial side of c-sectioned leaves, together with a thickened root endodermis in comparison with inland fescues (Baumeister and Merten, 1981; Ortuñez and de la Fuente, 2010; Martinez-Segarra et al, 2017)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
