Serotonin alleviates selenium stress and reduces selenium accumulation in <i>Cyphomandra betacea</i> seedlings

To alleviate selenium (Se) stress, the effects of serotonin (SER, 150 μmol/L) on the growth and Se accumulation of <i>Cyphomandra betacea</i> seedlings under Se stress (1.0 mg/L) were assessed. The results indicated that SER increased the biomass and photosynthetic pigment content of <i>C. betacea</i> seedlings under Se stress, while reducing the antioxidant enzymes activities, root Se content, and shoot Se content. Compared with Se treatment, SER decreased the activities of superoxide dismutase (SOD) and peroxidase (POD) by 34.08% and 25.22%, respectively, and decreased the contents of root Se and shoot Se by 12.79% and 17.14%, respectively. Furthermore, correlation, principal component, and cluster analyses revealed that the root Se content, SOD activity, and POD activity were closely correlated with the shoot Se content. Therefore, SER can alleviate Se-induced toxicity, and inhibit the Se accumulation of <i>C. betacea</i> seedlings.