中文摘要：

[目的]探讨硼对植物铝胁迫的缓解机理，研究果胶对铝的吸附解吸特征及硼的影响。[方法]利用等温吸附法，研究pH3．5，25℃时，不同浓度硼处理后的果胶对铝的吸附解吸特性，并利用相关模型计算果胶对铝的吸附参数。[结果]随果胶浓度的上升，其对铝的吸附总量和解吸总量均显著上升，但单位果胶的吸附量和解吸量显著下降；随铝浓度的增加，果胶对铝的吸附量和解吸量也显著上升；硼处理果胶后，影响果胶对铝的吸附解吸特性，〈25μmol·L-1的低浓度硼处理后，果胶对铝的吸附量和解吸量随硼浓度的增加会显著减少，而当硼浓度〉25μmol·L-1时，随硼浓度的增加，果胶对铝的吸附量反而会增加，硼浓度为100μmol-L-1时，果胶对铝的吸附量甚至显著大于硼浓度为0的对照，再增加硼浓度至200μm01·L-1，果胶对铝的吸附量又开始减少，果胶对铝的吸附或许已经达到饱和。利用Langrauir、Freund lich方程较好地拟合了无硼和加硼条件下果胶对铝的吸附过程，由Langmuir模型计算的最大吸附量分别是5．757mg·g-1和0．160mg·g-1，Freundlich方程拟合所得参数17分别为1．4702和-0．1758，说明硼与果胶RG—n的交联作用强烈影响果胶对A1”的吸附。[结论]pH3．5，25℃时，低浓度的硼（〈25μmol·L-1）可有效抑制果胶对铝的吸附，而高浓度的硼（〉25gmol·L-1）则促进果胶对铝的吸附。

英文摘要：

[Objective ] The influence of boron on adsorption and desorption of aluminum in pectin were studied in order to probe the possible mechanism of boron in alleviating aluminum toxicity. [ Method] Isothermal adsorption method was conducted to study the influence of different concentrations of boron on the adsorption/desorption of aluminum in pectin under the conditions of pH 3.5 and 25＂C. [Result] The total amount of aluminum adsorpted/desorpted in pectin significantly increased with the increase of pectin in equilibrium solution, but it significantly decreased in unit pectin. The amount of aluminum adsorpted/desorpted increased significantly with the increase of aluminum concentration as well. Boron pretreatment affected the characteristics of aluminum adsorption/desorption in pectin. Low concentration of boron less than 25 μmol.L-1 inhibited the adsorption/desorption of aluminum in pectin while the opposite was found at concentration higher than 25 μmol.L·-1. When boron concentration was 100 μmol·L-1, the amount of aluminum adsorption in pectin was even more than that of the control without boron. But aluminum adsorption in pectin reduced when boron concentration was 200 μmol.L-1, suggesting that pectin aluminum adsorption reached saturation. The curves of aluminum adsorption could be well described by both Langmuir and Freundlich isotherm adsorption equations with determination correlation coefficient R2 over 0.97. The maximum adsorption capacity calculated by Langmuir decreased from 5.757 mg.g1 to 0.160 mg·gq after adding boron, and the parameters of derived by Freundlich equation were 1.4702 and -0.1758, respectively, which indicatedthat the cross-linking of pectin RG- H with boron affected strongly on aluminum adsorption in pectin. [ Conclusion ] Boron could effectively inhibit aluminum adsorption in pectin at low concentration, while promote aluminum adsorption in pectin at high concentration.