Cadmium foliar application affects wheat Cd, Cu, Pb and Zn accumulation

Area of Science:

• Agricultural Science
• Environmental Science
• Plant Science

Background:

• Cadmium (Cd) contamination in soil poses risks to crop safety and human health.
• Wheat (Triticum aestivum) is a vital food crop susceptible to heavy metal accumulation.
• Understanding Cd's impact on nutrient distribution in wheat is critical for food security.

Purpose of the Study:

• To investigate the effects of foliar-applied Cd on Cd, Zn, Cu, and Pb accumulation in wheat.
• To assess the impact of Cd treatments on wheat biomass and grain yield.
• To determine the distribution and potential antagonistic effects of Cd on essential micronutrients in wheat.

Main Methods:

• Greenhouse experiment with wheat grown in contaminated soil.
• Foliar application of varying Cd concentrations (0-40 mg L⁻¹) during wheat development stages.
• Analysis of heavy metal (Cd, Zn, Cu, Pb) and nutrient concentrations in plant tissues (stems, leaves, glumes, grains) post-harvest.

Main Results:

• Foliar Cd application significantly reduced biomass and grain yield.
• Leaf and grain Cd concentrations increased substantially with Cd treatments.
• Grain Zn and Cu concentrations decreased under Cd exposure, indicating antagonistic effects, while Pb levels remained unchanged.
• Despite increased Cd concentration, grain Cd accumulation (concentration × yield) was not significantly affected by treatments.

Conclusions:

• Foliar Cd application negatively impacts wheat yield and nutrient profiles, particularly Zn and Cu.
• Competition for transporters and binding sites likely mediates Cd's antagonistic effect on Zn accumulation in wheat.
• Preventing Cd uptake into aboveground plant tissues is essential to mitigate risks to plant, animal, and human health.