Diversity and Functions of Endophytic Fungi Associated with Roots and Leaves of <i>Stipa purpurea</i> in an Alpine Steppe at Qinghai-Tibet Plateau

Abstract

<i>Stipa purpurea</i> is a unique and dominant herbaceous plant species in the alpine steppe and meadows on the Qinghai-Tibet Plateau (QTP). In this work, we analyzed the composition and diversity of the culturable endophytic fungi in <i>S. purpurea</i> according to morphological and molecular identification. Then, we investigated the bioactivities of these fungi against plant pathogenic fungi and 1- aminocyclopropane-1-carboxylate deaminase (ACCD) deaminase activities. A total of 323 fungal isolates were first isolated from <i>S. purpurea</i>, and 33 fungal taxa were identified by internal transcribed spacer primers and grouped into Ascomycota. The diversity of endophytic fungi in <i>S. purpurea</i> was significantly higher in roots as compared to leaves. In addition, more than 40% of the endophytic fungi carried the gene encoding for the ACCD gene. The antibiosis assay demonstrated that 29, 35, 28, 37 and 34 isolates (43.9, 53.1, 42.4, 56.1, and 51.5%) were antagonistic to five plant pathogenic fungi, respectively. Our study provided the first assessment of the diversity of culturedepending endophytic fungi of <i>S. purpurea</i>, demonstrated the potential application of ACCD activity and antifungal activities with potential benefits to the host plant, and contributed to high biomass production and adaptation of <i>S. purpurea</i> to an adverse environment.