单壁碳纳米管材料对水稻幼苗的毒性效应

随着碳纳米管材料(CNTs)被广泛地应用于工业和商业等多个领域,其将不可避免地进入到大气、水和土壤环境中,从而对生态系统结构和功能产生一些负面影响.为明确进入水环境中的碳纳米管材料对农业生产的潜在危险,本实验采用水培法,研究了不同浓度(10、20、40mg·L~(-1))的单壁碳纳米管材料(SWCNTs)对萌发期内水稻的发芽率、根长耐性指数和幼苗生长期内水稻的鲜重、叶绿素和可溶性蛋白的影响,以及单壁碳纳米管材料在水稻根部的累积.结果表明,在萌发期,胁迫处理4 d后,与对照相比,10、20、40 mg·L-1SWCNTs处理组对水稻发芽率没有任何抑制作用,但会延迟种子的发芽时间;水稻根长耐性指数随着单壁碳纳米管材料浓度的增加而下降.在幼苗生长期,胁迫处理30 d后,与对照相比,水稻鲜重随着单壁碳纳米管材料浓度的增加而分别下降14.2%、21.0%和38.8%;与此相类似,水稻叶绿素和可溶性蛋白质含量随着单壁碳纳米管材料浓度的增加而下降;另外,通过透射电镜观察(TEM)发现,SWCNTs颗粒分布在水稻幼苗根尖表皮细胞的细胞壁中.SWCNTs对水稻生长起抑制作用,且随着浓度的增加抑制作用逐渐增强.

Phytotoxicity of single-walled carbon nanotubes to rice seedling (oryza sativa L)

Along with the extensive usage of carbon nanotubes (CNTs) in industrial and commercial products, they are inevitably released into the atmosphere, water and soil environment, causing adverse effects on the structure and function of ecosystems. To evaluate the potential influence of CNTs to the water environment on agricultural production, a series of parameters, including germination rate, rice root length tolerance index, fresh weight, chlorophyll, soluble protein contents and accumulation of SWCNTs in rice seedlings grown in hydroponic solutions amended with SWCNTs suspensions at 10, 20 and 40 mg·L^-1, were measured. Results showed that, in the germination period, the germination rate did not change but seed germination was delayed in comparison with the control group. The root length tolerance index decreased at all SWCNTs concentrations. In the seedling growth period, the fresh weight decreased by 14.2%, 21.0% and 38.8% at SWCNTs concentrations of 10,20 and 40 mg·L^-1 respectively. In addition, the chlorophyll and soluble protein of rice decreased with the increase of SWCNTs concentration. Transmission electron microscopy (TEM) images illustrated that SWCNTs were observed in the cell wall of rice roots epidermal cells. SWCNTs inhibited rice seedlings growth, and the inhibition increased with the increase of the concentration of SWCNTs.