Effects of Dark Septate Endophytes Strain A024 on Damping-off Biocontrol, Plant Growth and the Rhizosphere Soil Enviroment of Pinus sylvestris var. mongolica Annual Seedlings.

Xun Deng,Saiyaremu Halifu,Ruiqing Song,Wenjing Yu,Xiaoshuang Song

doi:10.3390/plants9070913

Abstract

Dark septate endophytes (DSEs) exert a vital role in promoting plant growth, improving mineral absorption, biological disease control, and enhancing plant stress resistance. The effects of dark septate endophyte strain, Phialocephala bamuru A024 on damping-off biocontrol, plant development, nutrients within the rhizosphere soil, as well as bacterial communities in the annual seedlings of P. sylvestris var. Mongolica were studied. According to our findings, following P. bamuru A024 inoculation, the damping-off disease morbidity decreased significantly compared with control, some physiological indices such as β-1,3-glucanase, chitinase enzyme activity as well as a soluble protein and proline content in P. sylvestris var. mongolica were elevated under R. solani stress. After inoculation with P. bamuru A024, the biomass in seedlings, nutrients in soil, root structure index, together with activities of soil enzymes were remarkably up-regulated relative to control (p < 0.05). As suggested by the results of high-throughput sequencing, the microbial structure in the rhizosphere soil of the P. sylvestris var. mongolica showed significant differences (p < 0.05) after P. bamuru A024 inoculation compared to control treatment and the rhizosphere soil bacterial community structure after DSE A024 inoculation was positively correlated to the main soil nutrition indices.

Highlights

Plant endophytes widely exist in plants [1]
The inoculation of strain P. bamuru A024 can effectively control the damping-off lesions resulting from exposure to R. solani
The chitinase, CAT and POD activity as well as soluble protein content of the seedlings from the P. bamuru A024 treatment were increased by 63.21%, 59.45%, 149.63% and 49.49%, separately, relative to control treatment

Summary

Introduction

Dark septate endophytes (DSE) represent a major group on endophytes within plants characterized by a dark mycelium color and distinct septum. They colonize the epidermis, cortex, and even the intercellular space of vascular tissue of healthy plant roots to form symbionts without causing plant diseases [2,3]. The host range of dark septate endophytic fungi covers nearly 600 species of plants from 114 families and 320 genera. DSE colonization has been found in mycorrhizal plants as well as roots of traditional non-mycorrhizal plants such as Cyperaceae, Cruciferae, and Chenopodiaceae [4]. The main DSE fungi are the group of the Phialocephala fortinii s.l.—acephala applanata species complex (PAC) belonging to the ascomycetes. Several studies have reported that DSE fungi exhibit a positive effect on plant growth [7,8,9,10]

Methods

Results

Conclusion