Diversity of endophytic bacteria in wild rice (Oryza meridionalis) and potential for promoting plant growth and degrading phthalates

Li-Hui Liu; Tao Yuan; Jia-Yan Zhang; Guang-Xuan Tang; Huixiong Lü; Hai-Ming Zhao; Hui Li; Yan-Wen Li; Ce-Hui Mo; Zhi-Yuan Tan; Quan-Ying Cai

doi:10.1016/j.scitotenv.2021.150310

Diversity of endophytic bacteria in wild rice (Oryza meridionalis) and potential for promoting plant growth and degrading phthalates

Sci Total Environ. 2022 Feb 1;806(Pt 1):150310. doi: 10.1016/j.scitotenv.2021.150310. Epub 2021 Sep 14.

Authors

Li-Hui Liu¹, Tao Yuan², Jia-Yan Zhang³, Guang-Xuan Tang⁴, Huixiong Lü⁴, Hai-Ming Zhao³, Hui Li³, Yan-Wen Li³, Ce-Hui Mo³, Zhi-Yuan Tan⁵, Quan-Ying Cai⁶

Affiliations

¹ Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
² Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou 510642, China; State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China.
³ Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
⁴ College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
⁵ Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou 510642, China. Electronic address: zytan@scau.edu.cn.
⁶ Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China. Electronic address: caiqy@jnu.edu.cn.

PMID: 34583082
DOI: 10.1016/j.scitotenv.2021.150310

Abstract

Phthalates (PAEs) accumulated in agricultural soils and rice have increased human exposure risks. Microbial degradation could efficiently reduce the residue of organic pollutants in soil and crop plants. Here, we hypothesized that endophytic bacteria from wild rice have the potential for degradation of PAEs and plant growth promoting. The endophytic bacterial community and functional diversity in wild rice (Oryza meridionalis) were analyzed for the first time, and the potential for PAE degradation and plant growth promoting by endophytes were investigated. The results of Illumina high-throughput sequencing revealed that abundant endophytes inhabited in wild rice with Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria being the dominant phyla. Endophytic bacterial diversity and complexity were confirmed by isolation and clustering of isolates. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that endophytes exerted diverse functions such as plant growth promoting, xenobiotics biodegradation, pollution remediation and bacterial chemotaxis. Pure culture experiment showed that 30 isolated endophytic strains exhibited in vitro plant growth promoting activities, and rice plants inoculated with these strains confirmed their growth promoting abilities. Some endophytic strains were capable of efficiently degrading PAEs, with the highest removal percentage of di-n-butyl phthalate (DBP) up to 96.1% by Bacillus amyloliquefaciens strain L381 within 5 days. Synthetic community F and strain L381 rapidly removed DBP from soil (removing 91.0%-99.2% within 10 d and from rice plant slurry (removing 93.4%-99.2% within 5 d). These results confirmed the hypothesis and demonstrated the diversity of endophytic bacteria in wild rice with diverse functions, especially for plant growth promoting and removing PAEs. These multifunctional endophytic bacteria provided good alternatives to reduce PAE accumulation in crops and increase yield.

Keywords: Bioremediation; Endophytic bacterial community; Organic pollutant; Plant growth promoting; Wild rice.

MeSH terms

Bacteria / genetics
Biodegradation, Environmental
Endophytes
Humans
Oryza*
Plant Development
Plant Roots