作　　者： ; ; ; ; ; ; ; ;

机构地区： 佛山科学技术学院生命科学学院园艺系

出　　处： 《生态环境》 2005年第5期695-699,共5页

摘　　要： 根边缘细胞(Root border cells)是从根冠游离并聚集在根尖周围的一群特殊细胞,铝毒的作用部位正是根尖,因此推测边缘细胞在铝毒反应中起着重要作用.作者研究了不同铝浓度(0、50、100、250、500 (mol/L AlCl3(含0.1 mmol/L CaCl2, pH4.5)与离体豌豆(Pisum Sativum)根边缘细胞共培养1 h、2 h、4 h、6 h、8 h、24 h后根边缘细胞存活率、粘胶层厚度及细胞数量的变化,以揭示铝毒胁迫边缘细胞的响应.结果为:随着处理时间的延长,边缘细胞的存活率明显下降;在0～100 (mol/L铝浓度范围,边缘细胞存活率有随铝浓度升高而降低的趋势;8 h及24 h边缘细胞存活率为铝浓度500 (mol/L时显著高于0、50、100和250 (mol/L时,6 h边缘细胞存活率为250和500 (mol/L铝浓度时显著高于0、50、100 (mol/L AlCl3时.随处理时间延长,边缘细胞数量降低,铝浓度100,250和500 (mol/L时边缘细胞数量低于0和50 (mol/L时,且铝浓度越高,细胞数量越少;随处理时间延长和铝浓度升高,粘胶层相对面积增加,铝浓度500和250 (mol/L时粘胶层相对面积增加尤为明显.通过与pH 7.01水溶液及pH 4.50水溶液中粘胶层变化的比较,发现粘胶层在铝处理8 h后出现一个峰值,可能是粘胶物质的诱导合成和分泌.研究结果表明,铝毒对根边缘细胞具有致死效应,这种致死效应在一定浓度范围符合剂量依数性关系,高浓度时则边缘细胞存活率反而升高,这与根边缘细胞对铝毒作出的适应性响应--粘胶层的增厚和细胞降解增强有关.粘胶层起着保护和减轻边缘细胞铝毒的作用. Root border cells are recently defined alive population sloughed from root tips and loosely adhered in the water soluble mucilage, and the root tip is just the target of AI toxicity, thus it was guessed that border cells might function crucially in the response to AI toxicity. The cell viability, relative area of mucilage, and the cell number of border cells of pea （Pisum sativum） were detected after co-cultivation with 0, 50, 100, 250, 500 μmol/L AlCl3 （ 0.1 mmol/L CaCl2, pH 4.5 ） for 1 h, 2 h, 4 h, 6 h, 8 h, 24 h respectively.The results were： Cell viability decreased by the increase Al concentration from 0 to 100 μmol/L with time course, it was significantly higher at 500 μmol/L than at 0, 50, 100 and 250 μmol/L at 8 h and 24 h, as well as at 250 and 500 μmol/L than at 0, 50, 100 μmol/L. The cell number also decreased by the increase Al concentration and time course, and it was significantly lower at 100, 250 and 500 μmol/L than at 0 and 50 μmol/L. The relative area of mucilage extended by the increase of Al concentration and time course, and it was obviously higher at 500 and 250 μmol/L. A peak of relative area of mucilage was found at 8h Al treatment while comparing the relative area of mucilage of Al treatments to pH 7.01 water and pH 4.5 water solution that indicated the de novo synthesis and secretion of mucilage. Thus it showed that AI caused cell death at dosage dependent manner at lower AI concentration but not at higher concentration which might relate to the response of border cells to AI toxicity--the thickening of mucilage and the decomposing of border cells. Mucilage was indicated to function in protecting and/or alleviating AI cellular toxicity.

关 键 词： 豌豆 根边缘细胞 铝毒 粘胶层 存活率

领　　域： [生物学]