Early-stage growth and elemental composition patterns of Brassica napus L. in response to Cd–Zn contamination

Abstract

Soil contamination caused by the presence of Cd and the excess amount of Zn is a widespread concern in agricultural areas, posing significant risks to the growth and development of crops. In this paper, the early-stage development and metal (Cd and Zn) accumulation potential of rapeseed (Brassica napus L.) grown under different metal application schemes were assessed by determining radicle and hypocotyl length and the micro- and macro elemental composition of plantlets after 24, 72, and 120 h. The results indicated that the single and co-application of Cd and Zn significantly reduced the radicle and hypocotyl lengths. Accumulation intensity for Cd and Zn was affected by Cd and the combination of Cd and Zn in the solution, respectively. In addition, both metals significantly influenced the tissue Mn and had a minor effect on Cu and Fe concentrations. Both Cd and Zn significantly affected macro element concentrations by decreasing tissue Ca and influencing K and Mg concentrations in a dose- and exposure time-dependent manner. These findings specify the short-term and support the long-term use of rapeseed in remediation processes. However, interactions of metals are crucial in determining the concentration patterns in tissues, which deserves more attention in future investigations.