[Subcellular distribution of phenanthrene in plant root tissues].
Subcellular distribution of phenanthrene as a representative of polycyclic aromatic hydrocarbons (PAHs) in roots of five plants was investigated using a greenhouse hydroponic experiment. Results showed that, with the increase of the equilibrium concentrations of phenanthrene in solution from 0.056 to 0.39 mg x L(-1), the respective concentrations of phenanthrene in root, root cell organelle and cell wall increased from 26.85, 20.01 and 36.19 mg x kg(-1) to 56.91, 49.54 and 59.77 mg x kg(-1), and their concentration factors decreased from 357.14, 479.49, and 649.25 L x kg(-1) to 145.92, 127.04, and 153.26 L x kg(-1), respectively. The concentrations of phenanthrene in ryegrass root tissues followed the order of cell organelle > root > cell wall. In addition, concentrations of phenanthrene in cell organelle were generally 21%-163% higher than those in cell wall. As to the roots of five different tested plants growing in solution with initial phennathrene concentration of 1 mg x L(-1) after 144 h cultivation, the concentrations of phenanthrene were 48.64-145.2 mg x kg(-1) in root cell organelle, which were observed to be higher than those (15.86-74.49 mg x kg(-1)) in root cell wall. The subcellular distribution (%) of phenanthrene was in the following order: cell organelle > cell wall > cell soluble fraction. Based on the detected amounts of phenanthrene in subcellular fractions of plant root tissues, about 46%-53% and 31%-40% of phenanthrene were observed in root cell organelle and cell wall.