Scientific Reports (Nov 2020)

Identification of the rhizospheric microbe and metabolites that led by the continuous cropping of ramie (Boehmeria nivea L. Gaud)

  • Yanzhou Wang,
  • Siyuan Zhu,
  • Touming Liu,
  • Bing Guo,
  • Fu Li,
  • Xuehua Bai

DOI
https://doi.org/10.1038/s41598-020-77475-3
Journal volume & issue
Vol. 10, no. 1
pp. 1 – 11

Abstract

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Abstract Continuous cropping lowers the production and quality of ramie (Boehmeria nivea L. Gaud). This study aimed to reveal the metagenomic and metabolomic changes between the healthy- and obstacle-plant after a long period of continuous cropping. After 10 years of continuous cropping, ramie planted in some portions of the land exhibited weak growth and low yield (Obstacle-group), whereas, ramie planted in the other portion of the land grew healthy (Health-group). We collected rhizosphere soil and root samples from which measurements of soil chemical and plant physiochemical properties were taken. All samples were subjected to non-targeted gas chromatograph-mass spectrometer (GS/MS) metabolome analysis. Further, metagenomics was performed to analyze the functional genes in rhizospheric soil organisms. Based on the findings, ramie in Obstacle-group were characterized by shorter plant height, smaller stem diameter, and lower fiber production than that in Health-group. Besides, the Obstacle-group showed a lower relative abundance of Rhizobiaceae, Lysobacter antibioticus, and Bradyrhizobium japonicum, but a higher relative abundance of Azospirillum lipoferum and A. brasilense compared to the Health-group. Metabolomic analysis results implicated cysteinylglycine (Cys-Gly), uracil, malonate, and glycerol as the key differential metabolites between the Health- and Obstacle-group. Notably, this work revealed that bacteria such as Rhizobia potentially synthesize IAA and are likely to reduce the biotic stress of ramie. L. antibioticus also exerts a positive effect on plants in the fight against biotic stress and is mediated by metabolites including orthophosphate, uracil, and Cys-Gly, which may serve as markers for disease risk. These bacterial effects can play a key role in plant resistance to biotic stress via metabolic and methionine metabolism pathways.