Al^(3+)对荞麦离体根边缘细胞的作用

Effect of Al^(3+) toxicity on root border cells in vitro of buckwheat

以悬空气培法获得荞麦根边缘细胞,并收集、研究了边缘细胞的生物学活性和脱离根冠后对A l3+毒害的响应过程.结果表明,荞麦根边缘细胞绝大多数呈细杆状,少数呈弯曲的长条型.根长为25 mm左右时,边缘细胞的生物学活性最大,为(94±1)%.A l3+对离体边缘细胞有明显的毒害作用,用A l3+浓度为50μmol/L的溶液处理1~6 h就出现细胞死亡症状,在6 h之后毒害作用最大.系列浓度A l3+(0,12.5,25,50,100,200μmol/L,Ca2+浓度为0.1 mmol/L)处理12 h后,A l3+浓度为12.5μmol/L时处理就足以使离体边缘细胞大量死亡,这说明极其微量的A l3+浓度就可以显著影响离体根边缘细胞活性,也表明离体边缘细胞对A l3+的作用较为敏感,边缘细胞对铝毒响应的滞后性是细胞自身抗铝毒的一种生理反应.

To separate the Al^3＋ effects on border cells from those on root tips in buckwheat, experiments were carried out using border cells in vitro. The border ceils were pre-planted in aeroponic culture and detached from root tips. Most of root border ceils have a slender claval shape, and a few of them have a bend claval shape. Viability of border ceils reach the maximum of （94 ± 1 ） % when the root length was 25 mm. Al^3＋ treatment significantly decreases cell viability. The ceil death was found during 1 ～ 6 h Al^3＋ exposure time at a concentration of 50μmol/L, and the cell death was greatest after 6 h Al^3＋ treatment. Most of border cells in vitro had lost viability after treated with 12.5μmol/L for 12 h. These results suggested that border cells in vitro are sensitive to Al^3＋ toxicity, even at the lower Al^3＋ concentration. The lag phase response to Al^3＋ in border ceils in vitro could be due to a cellular self-protection response.