title: Characterization of phosphate accumulation in Lolium multiflorum for remediation of phosphorus-enriched soils.
abstract: Deterioration in water quality caused by the movement of excessive soil P has created a condition necessary for the development of a sustainable P remediation technology. In this investigation, the phytoremediation potential of Gulf and Marshall ryegrass (Lolium multiflorum) grown in a greenhouse was determined under varying conditions of soil P concentration, pH, and temperature. Both genotypes demonstrated P accumulations > or =1% shoot dry weight depending on soil P concentrations (0-10 g of P/kg of soil), with higher shoot P in Gulf than Marshall ryegrass. An increase in plant biomass was proportional to the increasing concentrations of P up to a level of 10 g of P/kg of soil. The effect of soil pH on plant uptake of P was noticeable with a significant rise in shoot P in acidic soil (pH 5.6) as compared to soil with pH 7.8. Significant differences were observed in the biomass productivity and shoot P accumulation at varying temperatures in both grass types. The patterns of acid phosphomonoesterase and phytase activities in plant roots were interesting, activities being 2-fold higher in alkaline soil than acidic soil in both genotypes. The effect of P supply on the enzyme activity was also distinct, as plants growing in a high P concentration showed higher activity (nearly 30%) than those growing under P deficiency conditions (with no addition of P). These results indicate that Gulf and Marshall ryegrass can accumulate high P under optimal conditions and thus reduce soil P concentrations in successive cropping.
authors.affiliation: Biotechnology Center, Department of Biology, Western Kentucky University, Bowling Green, Kentucky 42101, USA.
authors.forename: Nilesh C
authors.initials: NC
authors.lastname: Sharma
authors.forename: Shivendra V
authors.initials: SV
authors.lastname: Sahi
mesh_terms: D001673:Biodegradation, Environmental; D006863:Hydrogen-Ion Concentration; D008129:Lolium / Q000737:chemistry*; D010710:Phosphates / Q000302:isolation & purification* / Q000493:pharmacokinetics*; D018517:Plant Roots; D012989:Soil Pollutants / Q000302:isolation & purification* / Q000493:pharmacokinetics*; D014873:Water Pollutants / Q000302:isolation & purification* / Q000493:pharmacokinetics*
chemical_list: D010710:Phosphates; D012989:Soil Pollutants; D014873:Water Pollutants