Mechanisms of chloride to promote the uptake and accumulation of cadmium in rice (Oryza sativa L.)

Sci Total Environ. 2024 May 20:926:172046. doi: 10.1016/j.scitotenv.2024.172046. Epub 2024 Mar 27.

Abstract

Cadmium (Cd) contamination in rice ecosystems posed a critical challenge to global food security and environmental health. This study aimed to unveil the key mechanisms trough hydroponic experiments by which chloride (Cl-) promoted the absorption and accumulation of cadmium (Cd) in rice plants. The findings elucidated that the addition of Cl- increased Cd uptake by rice roots (5.1 % ∼ 61 %), acting both directly by enhancing root morphology and indirectly through regulating of the main transporter genes of Cd. The study unveiled that Cl- addition significantly improves Cd bioavailability in roots, which was discernible through the augmentation of Cd concentration and proportion in subcellular fractions, coupled with elevated energy values in key cellular components. Moreover, Cl- addition further augmented the intricate process of Cd transport from roots to shoots (16.1- 86.7 %), which was mainly attributed to the underexpression of OsHMA3 and the decrease in the formation of sulfuhydryl substances. This research provides a comprehensive understanding of the complex mechanisms governing Cd dynamics in rice plants in the presence of Cl-. By elucidating these processes, our findings not only contribute to fundamental knowledge in plant metal uptake but also hold promising implications for mitigating Cd contamination in rice cultivation systems.

Keywords: Cadmium; Chloride; Rice ecosystems; Transport; Uptake.

MeSH terms

  • Biological Transport
  • Cadmium
  • Chlorides
  • Ecosystem
  • Oryza* / physiology
  • Plant Roots
  • Soil Pollutants*

Substances

  • Cadmium
  • Chlorides
  • Soil Pollutants