Selenium accumulation characteristics ofCyphomandra betacea(Solanum betaceum) seedlings

A pot experiment was conducted to study the selenium (Se) accumulation characteristics and the tolerance ofCyphomandra betacea(Solanum betaceum) seedlings under different soil Se concentrations. The 5 mg/kg soil Se concentration increased theC. betaceaseedling biomass and photosynthetic pigment contents (chlorophylla, chlorophyllb, total chlorophyll, and carotenoid), whereas the other soil Se concentrations (10, 25, and 50 mg/kg) inhibited seedling growth. Increases in the soil Se concentrations tended to decrease the superoxide dismutase activity and soluble protein content, but had the opposite effect on the peroxidase and catalase activities. The 5, 10, and 25 mg/kg soil Se concentrations decreased the DNA methylation levels ofC. betaceaseedlings because of an increase in demethylation patterns (versus 0 mg/kg), whereas the 50 mg/kg soil Se concentration increased the DNA methylation levels because of an increase in hypermethylation patterns (versus 0 mg/kg). Increases in the soil Se concentrations were accompanied by an increasing trend in the Se content ofC. betaceaseedlings. Moreover, the amount of Se extracted by the shoots was highest for the 25 mg/kg soil Se concentration. Therefore,C. betaceamay be able to accumulate relatively large amounts of Se and its growth may be promoted in 5 mg/kg soil Se.