Ca2+对pb2+胁迫下板蓝根种子萌发及幼苗生理特性的影响

摘要

The effects of different Ca2+ levels(0,80,160,320 mg/L) on seed germination, SOD,POD activity and protein mass fraction of Radix Isatidis seedlings under different Pb2+ stress levels(0,100, 500 mg/L) were studied by petri dish germination method. The results showed that low mass concentration of Ca2+ (80, 160 mg/L) could ease Pb2+ poison, and significantly increase the seed germination rate, germination energy, germination index, vigour index, promote seedling SOD,POD activity and protein content, and the best result was obtained with 80 mg/L of Ca2+. The influence of Ca2+ on the Pb2+ toxicity was weakened at high Pb2+ mass concentration. Seed germination, SOD, POD activity and protein mass fraction of Radix Isatidis seedlings was inhibited under high concentration of Ca2+ (320 mg/L). These result suggested that the low mass concentration of Ca2+could be advantageous against Pb2+ toxicity, and could confer tolerance to Pb2+ stress in plant. The high mass concentration of Ca2+ and Pb2+ could produce synergistic toxicity on Radix Isatidis.%为探讨Ca2+缓解pb2+胁迫的机制,采用培养皿发芽法,研究Pb2+(0、100、500 mg/L)胁迫下不同质量浓度的Ca2+(0、80、160、320 mg/L)对板蓝根种子萌发及幼苗POD、SOD活性及蛋白质质量分数的影响.结果表明,低质量浓度的Ca2+(80、160 mg/L)可缓解pb2+毒害,显著提高板蓝根种子的发芽率、发芽势、发芽指数、活力指数,促进蛋白质质量分数的增加,提高SOD、POD活性,且Ca2+ 80 mg/L缓解效果最好,缓解能力随pb2+质量浓度的升高有所下降；高质量浓度的Ca2+ (320 mg/L)与Pb2+作用,反而抑制板蓝根种子的萌发,幼苗的POD、SOD活性及蛋白质质量分数下降.低质量浓度Ca2+可以显著提高板蓝根的抗性,对pb2+毒害起缓解作用,高质量浓度的Ca2+与pb2+对板蓝根起协同毒害作用.