Physiological and transcriptomic analyses reveal the cadmium tolerance mechanism of Miscanthus lutarioriparia

PLoS One. 2024 May 15;19(5):e0302940. doi: 10.1371/journal.pone.0302940. eCollection 2024.

Abstract

Miscanthus lutarioriparia is a promising energy crop that is used for abandoned mine soil phytoremediation because of its high biomass yield and strong tolerance to heavy metals. However, the biological mechanism of heavy metal resistance is limited, especially for applications in the soil restoration of mining areas. Here, through the investigation of soil cadmium(Cd) in different mining areas and soil potted under Cd stress, the adsorption capacity of Miscanthus lutarioriparia was analyzed. The physiological and transcriptional effects of Cd stress on M. lutarioriparia leaves and roots under hydroponic conditions were analyzed. The results showed that M. lutarioriparia could reduce the Cd content in mining soil by 29.82%. Moreover, different Cd varieties have different Cd adsorption capacities in soils with higher Cd concentration. The highest cadmium concentrations in the aboveground and belowground parts of the plants were 185.65 mg/kg and 186.8 mg/kg, respectively. The total chlorophyll content, superoxide dismutase and catalase activities all showed a trend of increasing first and then decreasing. In total, 24,372 differentially expressed genes were obtained, including 7735 unique to leaves, 7725 unique to roots, and 8912 unique to leaves and roots, which showed differences in gene expression between leaves and roots. These genes were predominantly involved in plant hormone signal transduction, glutathione metabolism, flavonoid biosynthesis, ABC transporters, photosynthesis and the metal ion transport pathway. In addition, the number of upregulated genes was greater than the number of downregulated genes at different stress intervals, which indicated that M. lutarioriparia adapted to Cd stress mainly through positive regulation. These results lay a solid foundation for breeding excellent Cd resistant M. lutarioriparia and other plants. The results also have an important theoretical significance for further understanding the detoxification mechanism of Cd stress and the remediation of heavy metal pollution in mining soil.

MeSH terms

  • Biodegradation, Environmental
  • Cadmium* / metabolism
  • Cadmium* / toxicity
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant* / drug effects
  • Mining
  • Plant Leaves / drug effects
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Poaceae* / drug effects
  • Poaceae* / genetics
  • Poaceae* / metabolism
  • Soil / chemistry
  • Soil Pollutants* / metabolism
  • Soil Pollutants* / toxicity
  • Stress, Physiological
  • Transcriptome

Grants and funding

This research was funded by Independent Research fund of Key Laboratory of Industrial Dust Prevention and Control & Occupational Health and Safety (Anhui University of Science and Technology) (NO.EK20202002), the Independent Research fund of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining (Anhui University of Science and Technology) (NO.EC2021007) and the Postdoctoral Science Foundation of China (2019M662719)." The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.