Effect of cadmium on the molecular and morpho-physiological traits of Pisum sativum L.

Cadmium (Cd) attracts many researchers because of its potential toxicity to humans. It is available in the soil in high concentrations and can cause physiological, morphological and molecular damage to plants. This study investigated the effect of different concentrations of Cd on the DNA as well as the morphological and physiological traits of pea (Pisum sativum). Inter simple sequence repeat (ISSR) markers were utilized to detect the effect of Cd on the genomic DNA of pea. Two ISSR primers (UBC-26 and UBC-35) resulted in highly clear and reproducible bands. The unique polymorphic bands produced with primer UBC-26 were 250 bp, 450 bp and 600 bp in the control but disappeared under the low, medium and high concentrations of Cd. Moreover, the unique polymorphic bands produced with primer UBC-35 were of sizes of 1500 bp and 2000 bp in the control but disappeared in the low, medium and high concentrations, indicating a genotoxic effect of Cd on pea DNA. The toxicity of Cd also negatively affected the morphological traits of roots, stems, leaves, seeds, flowers and fruit, and their physiological traits. The concentration of some mineral elements, chlorophyll, carotene, sugars, lipids, protein and the activity of some enzymes (glutathione peroxidase, catalase, superoxide dismutase, glutathione reductase, ascorbate peroxidase) decreased compared with the control responding to the Cd toxicity. The study reveals the environmental hazards of Cd on the molecular, morphological and physiological traits of P. sativum.