芦苇化感物质对藻类细胞膜选择透性的影响

以藻类渗出的K⁺、Mg²⁺、Ca²⁺浓度为表征，以ICP-MS检测为手段，研究了芦苇抑藻化感物质2-甲基乙酰乙酸乙酯(eathyl-2-methyl acetoacetate, EMA)对铜绿微囊藻、蛋白核小球藻和普通小球藻细胞膜选择透性的影响. 结果表明, 在实验条件下, 铜绿微囊藻和蛋白核小球藻细胞经煮沸完全破坏细胞膜时K⁺渗出量为1 .45、1 .59 μg·(10⁹ cell)^-1, 当EMA浓度为2 mg·L^-1时, 铜绿微囊藻和蛋白核小球藻的K⁺渗出量为1 .38、1 .40 μg·(10⁹ cell)^-1，当EMA浓度为4 mg·L^-1时, 铜绿微囊藻和蛋白核小球藻的K⁺渗出量为1 .44、1 .58 μg·(10⁹ cell)^-1，离子渗出量达到完全破坏细胞膜最大渗出量的95%以上. EMA浓度为4 mg·L^-1时，普通小球藻的细胞内K⁺渗出量为0 .64 μg·(10⁹ cell)^-1, 仅为完全破坏细胞膜后K⁺渗出量的31 .5%. EMA对Mg²⁺、Ca²⁺的渗出量的影响规律与K⁺相同. EMA破坏了铜绿微囊藻和蛋白核小球藻的细胞膜，但对普通小球藻的细胞膜透性没有显著影响.这是EMA选择性抑藻的机理之一.

Effects of Allelochemical Isolated from Phragmites communis on Algal Membrane Permeability

Efflux of K+, Mg2+, Ca2+ ions from algal cells as signals of cell membrane permeability, inductively coupled plasma mass spectrometry (ICP-MS) as detection method of ions, the present research investigated effects of allelochemical eathyl-2-methyl acetoacetate (EMA) isolated from Phragmites communis on cell membrane permeability of Microcystis aeruginosa, Chlorella pyrenoidosa and Chlorella vulagaris. The results showed that, when the cells were boiled for 10 min and the membrane was destroyed absolutely, the K+ efflux of M. aeruginosa and C. pyrenoidosa were 1.45 and 1.59 microg x (10(9) cell) (-1), respectively. When the concentration of EMA was 2 mg x L(-1), the K+ efflux of M. aeruginosa and C. pyrenoidosa were 1.38 and 1.40 microg x (10(9) cell)(-1), respectively. The K+ efflux of M. aeruginosa and C. pyrenoidosa reached 1.44 and 1.58 microg x (10(9) cell)(-1) while the EMA was 4 mg x L(-1). When the concentrations were 2 mg x L(-1) or 4 mg x L(-1) the K+ efflux reached more than 95% of the total ion amount in M. aeruginosa and C. pyrenoidosa cells. But when EMA concentration was 4 mg x L(-1), K+ efflux of C. vulagaris was 0.64 microg x (10(9) cell)(-1), which was only 31.5% of total K+ amount in C. vulagaris. Effects EMA on efflux of Mg2+ and Ca2+ were similar to those of K+. The results indicated that EMA destroyed the cell membrane of M. aeruginosa and C. pyrenoidosa but not C. vulagaris. This is one of the mechanisms of EMA species-selective antialgal.