几种植物根亚细胞中菲的分配

以菲为多环芳烃(PAHs)代表物,采用温室水培试验方法,研究了黑麦草、苏丹草、墨西哥玉米、高羊茅、三叶草等5种植物根亚细胞中菲的分配作用.结果表明,经144h培养,随着培养液中菲平衡浓度由0.056mg·L-1增至0.39mg·L-1,黑麦草根、细胞壁、细胞器中菲的含量分别从26.85、20.01和36.19mg·kg-1增大到56.91、49.54和59.77mg·kg-1,富集系数则分别由357.14、479.49和649.25L·kg-1降低到145.92、127.04和153.26L·kg-1.黑麦草根及亚细胞组分中菲的含量大小为细胞器根细胞壁,其中细胞器中菲含量要比细胞壁高21%～163%.水中菲的起始浓度均为1mg·L-1时,144h后,供试5种植物根细胞器中菲的含量(48.64～145.2mg·kg-1)均大于细胞壁(15.86～74.49mg·L-1).5种植物根亚细胞中菲分配的比例大小顺序为细胞器细胞壁可溶部分;其中,根内46%～53%和31%～40%的菲分别分布在细胞器和细胞壁中.

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·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·kg^-1 to 56.91, 49.54 and 59.77 mg·kg^-1, and their concentration factors decreased from 357.14, 479.49, and 649.25 L·kg^-1 to 145.92, 127.04, and 153.26 L·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·L^-1 after 144 h cultivation, the concentrations of phenanthrene were 48.64 -145.2 mg·kg^-1 in root cell organelle, which were observed to be higher than those (15.86 -74.49 mg·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.