酸雨胁迫对番茄叶片细胞膜透性的影响

摘要

采用番茄品种'倍盈'为材料,运用人工模拟酸雨研究不同强度酸雨(pH3.0、pH3.5、pH5.6)胁迫对'倍盈'叶片细胞质膜透性的影响.结果表明:酸雨处理使番茄叶片超氧化物歧化酶(SOD)的活性、丙二醛(MDA)的含量及细胞质膜透性显著上升,可溶性蛋白的含量显著下降.胁迫停止后SOD的活性逐渐下降,停止胁迫后20 d,pH3.0与pH3.5处理均显著低于pH5.6(CK);可溶性蛋白的含量pH3.0与pH3.5多呈现波动性的上升,至停止胁迫后15 d,pH3.0、pH3.5与pH5.6处理之间无显著差异.丙二醛的含量则呈现波动式上升,停止胁迫后20 d,pH3.5与pH5.6差异不显著,而pH3.0显著高于pH5.6;细胞质膜透性pH3.5表现先上升后下降的现象,pH3.0表现下降趋势的现象,但至停止胁迫后20 d,pH3.0、pH3.5与pH5.6之间无显著差异;pH值3.0和pH值3.5的叶片伤害率均随时间的延长而呈现下降的趋势,至停止胁迫后10 d以后基本处于一个较稳定的水平;从番茄植株的外部形态来看,pH3.0酸雨处理在胁迫停止后20 d,仍呈现叶片黄化、枯萎状态,说明pH3.0酸雨胁迫产生不可逆的伤害;而pH3.5酸雨胁迫处理下'倍盈'表现出较好的自我修复能力.%Effects of simulated acid rain(SiAR) at pH 3.0 and 3.5, along with pH 5.6 (CK), on the membrane permeability of cells in leaves of Brothin tomato were investigated.The results showed that the SOD activity, malondialdehyde (MDA) content, and cell membrane permeability of the tomato leaves increased significantly after SiAR treatments.But, the soluble protein decreased significantly due to the treatments.SOD activity in the leaves declined gradually once the stress was stopped.It became significantly lower than that of control, 20ds after the cessation.MDA content in the leaves treated by pH3.5 SiAR fluctuated with a slight upward trend that was not significantly different from that of control.On the other hand, the pH3.0 treatment produced a significant difference between them after 20ds of removal of the stress.The pH 3.5 treatment caused an initial rise on the membrane permeability and follo wed by a decline, while pH3.0 gave a continual downward trend.However, 20ds after stress stopping, there were no significant differences on the permeability between either of them and control.The soluble protein content in the leaves had an up-and-down insignificant increasing tendency by SiAR treatments in 15 days after the treatment.The injuries on the leaves caused by SiAR declined following the treatments, and reached a constant level 10ds after the stress ceased.Judging by the appearance of the tomato plants, the leaf yellowing and withering persisted 20ds after cessation of the pH3.0 treatment, indicating that an irreversible damage had occurred to the plants by SiAR.In contrast, the tomato plants seemed capable of self-rejuvenation after a SiAR stress at pH3.5.