Mn accumulation and tolerance in Celosia argentea Linn.: a new Mn-hyperaccumulating plant species.

Identifying a hyperaccumulator is an important groundwork for the phytoextraction of heavy metal-contaminated soil. Celosia argentea Linn., which grew on a Mn tailing wasteland, was found to hyperaccumulate Mn (14 362mgkg(-1) in leaf dry matter) in this study. To investigate Mn tolerance and accumulation in C. argentea, a hydroponic culture experiment was conducted in a greenhouse. Results showed that the biomass and the relative growth rate of C. argentea were insignificantly different (p>0.05) at the Mn supply level ranging from 2.5mgL(-1) (control) to 400mgL(-1). Manganese concentrations in leaves, stems, and roots reached maxima of 20228, 8872, and 2823mgkg(-1) at 600mgMnL(-1), respectively. The relative rate of Mn accumulation increased by 91.2% at 400mgMnL(-1). Over 95% of the total Mn taken up by C. argentea was translocated to shoots. Thus, C. argentea exhibits the basic characteristics of a Mn-hyperaccumulator. This species has great potential to remediate Mn-contaminated soil cheaply and can also aid the studies of Mn uptake, translocation, speciation, distribution and detoxification in plants.