School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
Department of Environmental Engineering, Kumoh National Institute of Technology, Daehak-ro 61, Gumi, Gyeongbuk 730-701, Republic of Korea.
Environ Toxicol Pharmacol. 2014 Nov;38(3):922-31. doi: 10.1016/j.etap.2014.10.002. Epub 2014 Oct 17.
Metal oxide nanoparticles (NPs) can inhibit plant seed germination and root elongation via the release of metal ions. In the present study, two acute phytotoxicity tests, seed germination and root elongation tests, were conducted on cucumber seeds (Cucumis sativus) treated with bulk copper oxide (CuO) and CuO NPs. Two concentrations of bulk CuO and CuO NPs, 200 and 600ppm, were used to test the inhibition rate of root germination; both concentrations of bulk CuO weakly inhibited seed germination, whereas CuO NPs significantly inhibited germination, showing a low germination rate of 23.3% at 600ppm. Root elongation tests demonstrated that CuO NPs were much stronger inhibitors than bulk CuO. SELDI-TOF MS analysis showed that 34 proteins were differentially expressed in cucumber seeds after exposure to CuO NPs, with the expression patterns of at least 9 proteins highly differing from those in seeds treated with bulk CuO and in control plants. Therefore, these 9 proteins were used to identify CuO NP-specific biomarkers in cucumber plants exposed to CuO NPs. A 5977-m/z protein was the most distinguishable biomarker for determining phytotoxicity by CuO NPs. Principal component analysis (PCA) of the SELDI-TOF MS results showed variability in the modes of inhibitory action on cucumber seeds and roots. To our knowledge, this is the first study to demonstrate that the phytotoxic effect of metal oxide NPs on plants is not caused by the same mode of action as other toxins.
金属氧化物纳米颗粒（NPs）可以通过释放金属离子来抑制植物种子的萌发和根的伸长。在本研究中，对黄瓜种子（Cucumis sativus）进行了两种急性植物毒性试验，即种子萌发和根伸长试验，并用块状氧化铜（CuO）和 CuO NPs 处理。使用两种浓度的块状 CuO 和 CuO NPs（200 和 600ppm）测试根萌发的抑制率；两种浓度的块状 CuO 对种子萌发的抑制作用较弱，而 CuO NPs 则显著抑制了萌发，在 600ppm 时发芽率低至 23.3%。根伸长试验表明，CuO NPs 比块状 CuO 强得多的抑制剂。SELDI-TOF MS 分析表明，暴露于 CuO NPs 后，黄瓜种子中有 34 种蛋白质表达差异，其中至少 9 种蛋白质的表达模式与用块状 CuO 处理的种子和对照植物中的表达模式有很大不同。因此，这些 9 种蛋白质被用于鉴定暴露于 CuO NPs 的黄瓜植物中 CuO NP 特异性的生物标志物。5977-m/z 蛋白是确定 CuO NPs 对植物产生毒性的最具区分性的生物标志物。SELDI-TOF MS 结果的主成分分析（PCA）表明，CuO NPs 对黄瓜种子和根的抑制作用模式存在差异。据我们所知，这是第一项表明金属氧化物 NPs 对植物的植物毒性效应不是由与其他毒素相同的作用模式引起的研究。
