Arbuscular mycorrhizal fungi alter microbiome structure of rhizosphere soil to enhance maize tolerance to La

Lijun Hao; Zhechao Zhang; Baihui Hao; Fengwei Diao; Jingxia Zhang; Zhihua Bao; Wei Guo

doi:10.1016/j.ecoenv.2021.111996

Arbuscular mycorrhizal fungi alter microbiome structure of rhizosphere soil to enhance maize tolerance to La

Ecotoxicol Environ Saf. 2021 Apr 1:212:111996. doi: 10.1016/j.ecoenv.2021.111996. Epub 2021 Feb 3.

Authors

Lijun Hao¹, Zhechao Zhang¹, Baihui Hao¹, Fengwei Diao¹, Jingxia Zhang¹, Zhihua Bao¹, Wei Guo²

Affiliations

¹ Inner Mongolia Key Laboratory of Environmental Pollution Control and Waste Resource Recycle, Ministry of Education Key Laboratory of Ecology and Resource use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.
² Inner Mongolia Key Laboratory of Environmental Pollution Control and Waste Resource Recycle, Ministry of Education Key Laboratory of Ecology and Resource use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China. Electronic address: ndguowei@163.com.

PMID: 33545409
DOI: 10.1016/j.ecoenv.2021.111996

Abstract

Rhizosphere microbes are essential partners for plant stress tolerance. Recent studies indicate that arbuscular mycorrhizal fungi (AMF) can facilitate the revegetation of soils contaminated by heavy metals though interacting with rhizosphere microbiome. However, it is unclear how AMF affect rhizosphere microbiome to improve the growth of plant under rare earth elements (REEs) stress. AMF (Claroideoglomus etunicatum) was inoculated to maize grown in soils spiked with Lanthanum (0 mg kg^-1, La0; 10 mg kg^-1, La10; 100 mg kg^-1, La100; 500 mg kg^-1, La500). Plant biomass, nutrient uptake, REE uptake and rhizosphere bacterial and fungal community were evaluated. The results indicated that La100 and La500 decreased significantly root colonization rates and nutrition uptake (K, P, Ca and Mg content). La500 decreased significantly α-diversity indexes of bacterial and fungal community. AMF enhanced significantly the shoot and root fresh and dry weight of maize in all La treatments (except for the root fresh and dry weight of La0 and La10 treatment). For La100 and La500 treatments, AMF increased significantly nutrition uptake (K, P, Ca and Mg content) in shoot of maize by 27.40-441.77%. For La500 treatment, AMF decreased significantly shoot La concentration by 51.53% in maize, but increased significantly root La concentration by 30.45%. In addition, AMF decreased bacterial and fungal Shannon index in La0 treatment, but increased bacterial Shannon index in La500 treatment. Both AMF and La500 affected significantly the bacterial and fungal community composition, and AMF led to more influence than La. AMF promoted the enrichment of bacteria, including Planomicrobium, Lysobacter, Saccharothrix, Agrococcus, Microbacterium, Streptomyces, Penicillium and other unclassified genus, and fungi (Penicillium) in La500, which showed the function for promoting plant growth and tolerance of heavy metal. The study revealed that AMF can regulate the rhizosphere bacterial and fungal composition and foster certain beneficial microbes to enhance the tolerance of maize under La stress. Phytoremediation assisted by AMF is an attractive approach to ameliorate REEs-contaminated soils.

Keywords: Arbuscular mycorrhizal fungi (AMF); Lanthanum (La); Rhizosphere bacterial community; Rhizosphere fungal community.

MeSH terms

Bacteria / growth & development
Biodegradation, Environmental
Biomass
Fungi / growth & development*
Glomeromycota / growth & development
Lanthanum / analysis
Lanthanum / toxicity*
Microbiota
Mycorrhizae / physiology*
Plant Roots / chemistry
Plant Roots / microbiology
Rhizosphere*
Soil / chemistry
Soil Microbiology*
Soil Pollutants / analysis
Soil Pollutants / toxicity*
Zea mays / drug effects*
Zea mays / growth & development
Zea mays / microbiology

Substances

Soil
Soil Pollutants
Lanthanum

Supplementary concepts

Claroideoglomus etunicatum