1 research outputs found
Root-Colonizing Endophytic Fungi of the Dominant Grass Stipa krylovii From a Mongolian Steppe Grassland
In several terrestrial ecosystems such as grasslands, plants live together with various
root-colonizing dark septate endophytes (DSEs), fungi that are relatively frequent
colonizers of healthy belowground tissues of plants in these environments. They are
important members of the plant microbiota and may have various effects on plant
survival under different stress conditions; however, their general functions in relation
to plants and the greater ecosystem remain elusive. Although an increasing number
of studies has been published focusing on DSEs in Asian grasslands, our knowledge
is limited. Especially in Mongolia, where the steppe region represents a significant
area, information is not available on these root colonizers. In this study, we aimed to
characterize DSEs of a common dominant gramineous plant species, Stipa krylovii in a
semiarid grassland of Mongolia. Root samples were collected in a natural steppe and
were processed for isolation of fungal endophytes. For molecular identification of the
isolates, the internal transcribed spacer (ITS) region of the nrDNA was obtained for all
the isolates investigated; furthermore, the partial translation elongation factor 1-a (TEF)
gene and large subunit (LSU) and small subunit (SSU) of rDNA were also amplified and
sequenced in case of representative isolates. In vitro tests were used to examine the
rough symbiotic nature of the fungi, and root colonization was visualized. A majority of
the 135 isolates examined in detail was found to belong to several orders of Ascomycota
(110 isolates) and some to Basidiomycota (25 isolates). A significant number of the
isolates represented presumably novel taxa, and dominant similarities of the lineages
have been found with relatively frequent and known grass root endophytes of semiarid
areas in other geographic regions. These endophytes included Periconia macrospinosa,
Microdochium bolley, and Darksidea, the genus of which comprised one fourth of the
isolates. We found numerous lineages, which have been detected not only from Asian
steppe ecosystems, but also from prairies in North America and sandy grasslands in
Europe. Therefore, our results strengthen the hypothesized worldwide presence of a
common and dominant core group of a DSE community in arid and semiarid grasslands