Integrated cell wall and transcriptomic analysis revealed the mechanism underlying zinc-induced alleviation of cadmium toxicity in Cosmos bipinnatus

Plant Physiol Biochem. 2024 Sep:214:108940. doi: 10.1016/j.plaphy.2024.108940. Epub 2024 Jul 15.

Abstract

Plant growth is severely harmed by cadmium (Cd) contamination, while the addition of zinc (Zn) can reduce the toxic effects of Cd. However, the interaction between Cd and Zn on the molecular mechanism and cell wall of Cosmosbipinnatus is unclear. In this study, a transcriptome was constructed using RNA-sequencing. In C. bipinnatus root transcriptome data, the expression of 996, 2765, and 3023 unigenes were significantly affected by Cd, Zn, and Cd + Zn treatments, respectively, indicating different expression patterns of some metal transporters among the Cd, Zn, and Cd + Zn treatments. With the addition of Zn, the damage to the cell wall was reduced, both the proportion and content of polysaccharides in the cell wall were changed, and Cd accumulation was decreased by 32.34%. In addition, we found that Cd and Zn mainly accumulated in pectins, the content of which increased by 30.79% and 61.4% compared to the CK treatment. Thus, Zn could alleviate the toxicity of Cd to C. bipinnatus. This study revealed the interaction between Cd and Zn at the physiological and molecular levels, broadening our understanding of the mechanisms of tolerance to Cd and Zn stress in cosmos.

Keywords: Cd tolerance; Cosmos bipinnatus; Polysaccharide synthesis; Transcriptomic analysis; Zinc.

MeSH terms

  • Cadmium* / toxicity
  • Cell Wall* / drug effects
  • Cell Wall* / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant / drug effects
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Transcriptome / drug effects
  • Zinc* / metabolism
  • Zinc* / pharmacology
  • Zinc* / toxicity

Substances

  • Cadmium
  • Zinc