Manganese uptake and accumulation by two populations of Phytolacca acinosa Roxb. (Phytolaccaceae)

Phytolacca acinosa (Phytolaccaceae) is a recently discovered manganese hyperaccumulator plant from Southern China. Manganese uptake and accumulation by two contrasting populations of P. acinosa were investigated. One population (MP) was from Xiangtan manganese tailings and the other (NMP) was from a Magnolia grandiflora plantation with lower Mn status. In addition to these field investigations, seedlings of the two populations were raised under glasshouse conditions to study biomass production and Mn uptake from nutrient solutions supplemented with increasing amounts of Mn (5, 1000, 2000, 5000, and 8000 mumol L-1 Mn). Although, concentrations of Mn in the plant tissues (leaves, stems and roots) of P. acinosa (MP) and the associated soil from manganese tailings were significantly higher than those of the plant tissues and the soil collected in the clean site, significant differences were not found between the two populations of P. acinosa grown in nutrient culture. The two populations of seedlings showed similar growth responses, manganese uptake and accumulation when exposed to the same level of Mn supply for 45 days. All these results suggest that both high tolerance and hyperaccumulating ability of Mn in P. acinosa are constitutive properties. Furthermore, the plant grows rapidly, produces substantial biomass, and has broad ecological amplitude. P. acinosa, therefore, offers great potential for use in the phytoremediation of Mn-contaminated soils.