纳米氧化锌、硫酸锌和AM真菌对玉米生长的影响

纳米氧化锌(Zn O)是应用最为广泛但具有一定生物毒性的金属型纳米颗粒(nanoparticles,NPs)之一,而丛枝菌根(arbuscular mycorrhizal,AM)真菌能改善宿主植物矿质营养和增强宿主植物抗逆性,但纳米Zn O和其他锌污染物之间的关系以及AM真菌对其生物效应的影响目前尚不清楚.通过温室盆栽试验,研究了单一或复合施加纳米Zn O、ZnSO_4(500mg·kg~(-1))时接种AM真菌Funneliformis mosseae BEG 167对玉米生长的影响.结果表明,纳米Zn O对AM真菌侵染和玉米植株生长有一定抑制作用,表现出植物毒性,且与同浓度(500 mg·kg~(-1))下的ZnSO_4作用类似.与非菌根对照相比,接种AM真菌降低了玉米植株的Zn含量或Zn吸收量,且在复合处理中对玉米生长表现出较好的促生作用.结果首次表明,纳米ZnO与ZnSO_4在生物毒性上存在复杂的交互作用,而接种AM真菌在二者复合污染时对玉米具有一定的保护作用.

Effects of ZnO Nanoparticles, ZnSO4 and Arbuscular Mycorrhizal Fungus on the Growth of Maize

As one of the most widely used metal-based nanoparticles (NPs), ZnO NPs have been shown to be toxic to organisms. Arbuscular mycorrhizal (AM) fungi can improve mineral nutrition and increase the resistance of host plants. However, little is known on the interaction between ZnO NPs and other Zn pollutants, as well as the effect of AM fungi on their biological effects. The present greenhouse pot culture experiment studied the effects of inoculation with or without AM fungus Funneliformis mosseae BEG 167 on the growth of maize in soil supplemented with ZnO NPs and ZnSO₄ (500 mg ·kg^-1) seperately or in combination. The results showed that ZnO NPs inhibited mycorrhizal colonization and the growth of maize plants, showing similar phytotoxicity and effects to ZnSO₄ at the same concentration (500 mg ·kg^-1). Compared with the nonmycorrhizal controls, AM fungal inoculation decreased Zn concentrations or uptake in maize plants, and showed a better growth-promoting effect in the combination treatment. Our results showed for the first time that there was a complex interaction in their biological toxicity between ZnO NPs and ZnSO₄, while AM fungal inoculation exhibited a protective effect under combined pollution of ZnO NPs and ZnSO₄.