College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China.
J Hazard Mater. 2022 Apr 5;427:127868. doi: 10.1016/j.jhazmat.2021.127868. Epub 2021 Nov 24.
The effects of four water-soluble pyridinium-based ionic liquids (ILs) differing in alkyl side chain length, namely, N-ethyl pyridinium bromide ([EPy]Br), N-butyl pyridinium bromide ([BPy]Br), N-hexyl pyridinium bromide ([HPy]Br), and N-octyl pyridinium bromide ([OPy]Br), on the growth of maize seedlings were investigated for the first time. The results revealed that the phytotoxicity of these ILs was significantly correlated with their concentration and alkyl side chain length. The 8-day 50% inhibition values indicated that the toxicity increased as the length of the alkyl chain increased: [EPy]Br < [BPy]Br < [HPy]Br < [OPy]Br. In addition, root growth was found to be more sensitive to ILs than stem growth. In response to exposure to ILs of increasing concentration, we observed different trends in the pigment contents and specific antioxidant enzyme activities in maize seedlings, whereas the contents of malondialdehyde were significantly increased. In addition, RNA sequencing analysis, performed to examine the gene expression profiles of maize leaves under [HPy]Br and [OPy]Br treatments, revealed that a larger number of genes were differentially expressed in response to [OPy]Br treatment. Furthermore, pathway enrichment analysis revealed that both [HPy]Br and [OPy]Br treatments, and particularly the latter, caused a down-regulation of genes involved in photosynthesis and carbohydrate and nitrogen metabolism. Our findings thus indicate that pyridinium-based IL toxicity might be associated with oxidative stress and changes in gene expression profiles.
首次研究了四种不同烷基侧链长度的水溶性吡啶鎓基离子液体（ILs），即 N-乙基吡啶溴化物([EPy]Br)、N-丁基吡啶溴化物([BPy]Br)、N-己基吡啶溴化物([HPy]Br)和 N-辛基吡啶溴化物([OPy]Br)对玉米幼苗生长的影响。结果表明，这些 IL 的植物毒性与其浓度和烷基侧链长度显著相关。8 天 50%抑制值表明，毒性随烷基链长度的增加而增加：[EPy]Br < [BPy]Br < [HPy]Br < [OPy]Br。此外，发现根生长对 ILs 的敏感性比茎生长更高。在响应暴露于浓度增加的 ILs 时，我们观察到玉米幼苗中色素含量和特定抗氧化酶活性的不同趋势，而丙二醛含量显著增加。此外，为了研究 [HPy]Br 和 [OPy]Br 处理下玉米叶片的基因表达谱而进行的 RNA 测序分析表明，响应 [OPy]Br 处理有更多的基因表达差异。此外，途径富集分析表明，[HPy]Br 和 [OPy]Br 处理，特别是后者，导致与光合作用和碳水化合物及氮代谢相关的基因下调。因此，我们的研究结果表明，吡啶鎓基 IL 毒性可能与氧化应激和基因表达谱的变化有关。
