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

Sci Rep. 2020 Nov 23;10(1):20408. doi: 10.1038/s41598-020-77475-3.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azospirillum brasilense / growth & development
  • Azospirillum brasilense / metabolism*
  • Azospirillum lipoferum / growth & development
  • Azospirillum lipoferum / metabolism*
  • Boehmeria / metabolism*
  • Boehmeria / microbiology
  • Bradyrhizobium / growth & development
  • Bradyrhizobium / metabolism*
  • Crops, Agricultural
  • Dipeptides / metabolism
  • Gas Chromatography-Mass Spectrometry
  • Glycerol / metabolism
  • Humans
  • Lysobacter / growth & development
  • Lysobacter / metabolism*
  • Malonates / metabolism
  • Metabolomics / methods
  • Metagenomics / methods
  • Methionine / metabolism
  • Phosphates / metabolism
  • Rhizosphere
  • Soil / chemistry*
  • Soil Microbiology
  • Stress, Physiological
  • Uracil / metabolism

Substances

  • Dipeptides
  • Malonates
  • Phosphates
  • Soil
  • cysteinylglycine
  • Uracil
  • malonic acid
  • Methionine
  • Glycerol

Supplementary concepts

  • Bradyrhizobium japonicum
  • Lysobacter antibioticus