Effects of cadmium on growth, short-term photosynthetic acclimation and metal accumulation in radish plants (<i>Raphanus sativus L.</i>)

Abstract

Plants displaying heavy metal hyper-accumulation and high biomass could be used in phytoextraction. The present study utilises photosynthetic acclimation rates and morphological measurements to gauge cadmium toxicity in radish plants raised on nutrient solutions containing 0, 5, 10 and 20 µM CdCl2. Growth rates displayed a dose-dependent decline with cadmium exposure. Photosynthetic acclimation was significantly reduced compared to controls in all cadmium treatments. Inductively coupled plasma mass spectrometry was used to determine cadmium accumulation. In both the roots and shoots of the plant, cadmium levels were significantly higher than the controls in 10 and 20 µM treatments. Significantly more cadmium was distributed into the roots compared to shoots. A moderate tolerance for and reasonable accumulation of cadmium makes the radish a candidate for phytoremediation in marginally contaminated environments. Furthermore, the sensitivity of photosynthetic acclimation rates to cadmium exposure serves as a potential bioindicator of cadmium contamination.