Abstract

The effect of low molecular weight chitosans with a molecular weight (MW) of 5, 6, 10, 25, and 45 kDa and a deacetylation degree (DD) of 85–99% obtained by chemical depolymerization and enzymatic hydrolysis on the cells of the epidermis of pea leaves was analyzed. Low molecular weight chitosans induced damage to guard cells' plasma membrane, which was estimated from the change in its permeability for the fluorescent dye propidium iodide, and programmed death of epidermal cells determined from the destruction of cell nuclei. These effects are similar to those of commercial high molecular weight chitosan with an MW of 290 kDa and a DD of 90%, which was manifested at higher concentrations than with low molecular weight chitosan. The destructive effect of chitosan on the cells was predominantly DD-dependent, and it was not produced at concentrations up to 10 μg/mL inclusive. Low molecular weight chitosan enhanced the generation of reactive oxygen species in the epidermis, which was detected by monitoring the fluorescence of 2′,7′-dichlorofluorescein. The antioxidants nitroblue tetrazolium and propyl gallate inhibited this process, while Н₂О₂ accelerated it.

中文翻译：

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低分子量壳聚糖对豌豆叶表皮细胞的影响

摘要

通过化学解聚和酶促水解获得的分子量（MW）为5、6、10、25和45 kDa的低分子量壳聚糖的脱乙酰度（DD）为85–99％。分析了豌豆叶的表皮。低分子量的壳聚糖诱导了保卫细胞质膜的损伤，这是由其对荧光染料碘化丙啶的渗透性的变化估计的，而表皮细胞的程序性死亡是由细胞核的破坏确定的。这些效果类似于分子量为290 kDa且DD为90％的商品化高分子量壳聚糖，其浓度高于低分子量壳聚糖。壳聚糖对细胞的破坏作用主要取决于DD，并非以最高10μg/ mL的浓度产生。低分子量壳聚糖增强了表皮中活性氧的生成，这是通过监测2'，7'-二氯荧光素的荧光来检测的。抗氧化剂硝基蓝四唑和没食子酸丙酯抑制了这一过程，而Н₂ О ₂加速它。