Dark septate endophytes isolated from a xerophyte plant promote the growth of Ammopiptanthus mongolicus under drought condition

Xia Li,Lifeng Hou,Shaojie Wang,Xueli He,Ying Ren,Fang Su

doi:10.1038/s41598-018-26183-0

Abstract

Dark septate endophytes (DSE) may facilitate plant growth and stress tolerance in stressful ecosystems. However, little is known about the response of plants to non-host DSE fungi isolated from other plants, especially under drought condition. This study aimed to seek and apply non-host DSE to evaluate their growth promoting effects in a desert species, Ammopiptanthus mongolicus, under drought condition. Nine DSE strains isolated from a super-xerophytic shrub, Gymnocarpos przewalskii, were identified and used as the non-host DSE. And DSE colonization rate (30–35%) and species composition in the roots of G. przewalskii were first reported. The inoculation results showed that all DSE strains were effective colonizers and formed a strain-dependent symbiosis with A. mongolicus. Specifically, one Darksidea strain, Knufia sp., and Leptosphaeria sp. increased the total biomass of A. mongolicus compared to non-inoculated plants. Two Paraconiothyrium strains, Phialophora sp., and Embellisia chlamydospora exhibited significantly positive effects on plant branch number, potassium and calcium content. Two Paraconiothyrium and Darksidea strains particularly decreased plant biomass or element content. As A. mongolicus plays important roles in fixing moving sand and delay desertification, the ability of certain DSE strains to promote desert plant growth indicates their potential use for vegetation recovery in arid environments.

Highlights

Drought and desertification in China, especially in the northwest regions, are rapidly increasing and have become serious environmental problems limiting plant growth and revegetation[1,2]
Septate hyphae and microsclerotia-like structures in the roots of many plant species have been defined as DSE10,11, and they have been observed in the roots of approximately 600 plant species belonging to 110 families and 320 genera[11]
Typical dark septate endophytes (DSE) hyphae and microsclerotia structures were observed in the roots of G. przewalskii (Fig. 1)

Summary

Introduction

Drought and desertification in China, especially in the northwest regions, are rapidly increasing and have become serious environmental problems limiting plant growth and revegetation[1,2]. Similar to AMF, DSE exhibit positive effects on plant growth, water and nutrient uptake and increase the stress tolerance of host plants[9,13,14,15,16,17,18]. In our previous investigations in northwest China, DSE fungi were found to co-occur with multiple desert plants, especially in extreme arid environments. DSE fungi isolated from maize could act be an effective colonizer, and improved the growth and drought resistance of sorghum seedlings[34]. The distribution and abundance of DSE in (semi)arid regions have been widely investigated, studies of the association between DSE and desert plants under water stress are limited. The results showed that inoculation with DSE isolates stimulated the growth of Agropyron cristatum and Psathyrostachys juncea and inhibited the growth of Bouteloua gracillis under water deficiency

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Conclusion