纳米氧化铜对小麦根系生理生化行为的影响

摘要

To explore the effects of metal nanoparticles on plant growth, agar culture simulating soil was used to characterize the root elongation and relative physiological and biochemical behavior of wheat (Trilicum aesttvum L.) under stress of copper oxide nanoparticles (CuO NPs). The results showed that the inhibition of root elongation in agar was exponentially correlated with the concentration of CuO NPs, which was increased slightly at a lower concentration (10 mg/L) of CuO NPs but decreased greatly at a higher concentration (100 mg/L). It should be noted that the variation of superoxide dismutase (SOD) activity shared the same trend as the inhibition of root elongation under CuO NPs exposure. Furthermore, with increasing of CuO NPs from 1 to 100 mg/L, the content of malonaldehyde (MDA) continuously increased while the protein content sharply decreased in roots. These results demonstrated that the inhibition of root elongation could be mainly attributed to the peroxide injury of plant cell membrane under CuO NPs exposure. Interestingly, wheat root may exhibit the adaptive response through enhancing the root vitality to alleviate the phytotoxicity induced by CuO NPs.%为阐明纳米金属材料暴露对植物生长的影响及其作用机制,采用模拟土壤的琼脂培养方法研究了纳米氧化铜(CuONPs)对小麦(Triticum aestivum L.)根伸长及相关生理生化行为的影响.结果表明:小麦根伸长与CuO NPs暴露浓度之间存在指数相关关系,在低浓度CuO NPs (10 mg/L)暴露下得到一定程度促进,而在高浓度(100 mg/L)下受到强烈抑制.小麦根内超氧化物歧化酶(SOD)活性随CuO NPs暴露浓度的变化趋势与小麦根伸长具有一致性.另外,在1～100mg/L范围内,随着CuO NPs暴露浓度的升高,小麦根内丙二醛(MDA)含量不断增加,但植物蛋白含量急剧降低.以上结果说明CuO NPs对根伸长抑制主要是由于纳米材料暴露造成植物细胞膜氧化损伤,小麦能通过提高根系活力对CuO NPs暴露作出适应性应激响应以减少纳米材料毒性的伤害.