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A naturally selenium-accumulating Cardamine sp. is growing in Yutangba Selenium Mining Field, Enshi area, Hubei Province, China, where the geochemical environment is selenium-enriched and endemic selenosis ever occurred in humans. The present study investigated the characteristics of accumulation, speciation and quantity of selenium in Cardamine sp. with HPLC-ICP-MS. Results show that Cardamine sp. can accumulate Se at most 1427 mg/kg in seedling leaves. Even after the biomass incensement of growing up, the plant still could accumulate Se up to several hundred of mg/kg in concentration. Moreover, the biomass enrichment coefficient(BEC) of Se is exceedingly high, in the seedling leaves mostly, higher than 50 mg/kg; in the range of 43.7–68 mg/kg; and the lowest value is higher than 3 mg/kg in mature fronds. Se is present in the plant predominantly in form of Se Cys2 with the highest concentration in seeds; up to 1081 mg/kg as Se. In contrast, Se Cys2 levels are low during early growth period; they are 136.1 mg/kg as Se in seedling fronds and 39.4 mg/kg as Se in mature fronds, respectively. Se Met concentration is comparatively low; 10.6 mg/kg as Se in seedling frond and 5.3 mg/kg as Se in half mature fronds, respectively. This indicates that Cardamine sp. is extremely efficient in extracting Se from soil and translocating it into its above-ground biomass. Therefore, Cardamine sp., found in Yutangba Se Mining Field may be a new Se hyperaccumulator. It is still uncertain whether the Se-accumulation or detoxification of Cardamine sp. happens through the pathway of Se Cys methylated to form Se-methylseleno Cys or through the formation of Se-carboxymethyl- selenohomocysteine. Indeed, further study should be carried out on the determination of more Se species to explain the high Se hyperaccumulation in Cardamine sp.
A naturally selenium-accumulating Cardamine sp. Is growing in Yutangba Selenium Mining Field, Enshi area, Hubei Province, China, where the geochemical environment is selenium-enriched and endemic selenosis ever occurred in humans. The present study investigated the characteristics of accumulation, speciation and quantity of selenium in Cardamine sp. with HPLC-ICP-MS. Results show that Cardamine sp. can accumulate Se most 1427 mg / kg in seedling leaves. Even after the biomass incensement of growing up, the plant still could accumulate Se up to several hundred of mg / kg in concentration. Moreover, the biomass enrichment coefficient (BEC) of Se was exceedingly high, in the seedling leaves mostly, higher than 50 mg / kg; in the range of 43.7-68 mg / kg; and The lowest value is higher than 3 mg / kg in mature fronds. Se is present in the plant predominantly in form of Se Cys2 with the highest concentration in seeds; up to 1081 mg / kg as Se. In contrast, Se Cys2 levels are low during early growth they were 136.1 mg / kg as Se in seedling fronds and 39.4 mg / kg as Se in mature fronds, respectively. Se Met concentration was relatively low; 10.6 mg / kg as Se in seedling frond and 5.3 mg / kg as Se in It is extremely efficient in extracting Se from soil and translocating it into above ground-biomass. Therefore, Cardamine sp., found in Yutangba Se Mining Field may be a new Se hyperaccumulator. It is still uncertain whether the Se-accumulation or detoxification of Cardamine sp. happens through the pathway of Se Cys methylated to form Se-methylseleno Cys or through the formation of Se-carboxymethyl- selenohomocysteine. Indeed, further study should be carried out on the determination of more Se species to explain the high Se hyperaccumulation in Cardamine sp.