Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China; Research Center of Low Carbon Economy for Guangzhou Region, Jinan University, Guangzhou 510632, China.
J Hazard Mater. 2021 Jan 5;401:123412. doi: 10.1016/j.jhazmat.2020.123412. Epub 2020 Jul 8.
Potential adverse effects of nanoplastics (NPs) on marine organisms have received increased attention in recent years. In contrast, few data are available on terrestrial plants, especially on the mechanisms for transport of NPs in plants and phytotoxicity (at both phenotypic and molecular levels) of plants induced by NPs. To address this knowledge gap, we conducted a microcosm study in which hydroponically-cultured rice (Oryza sativa L.) seedlings were exposed to polystyrene (PS)-NPs at 0, 10, 50, and 100 mg L for 16 d and examined for morphological and physiological phenotypes and transcriptomics. Laser confocal scanning micrographs confirmed PS-NPs were uptaken by rice roots, greatly benefitted from the transport activity of aquaporin in rice roots. The significant enhancement (p < 0.05) of antioxidant enzyme activities reflected the oxidative stress response of rice roots upon exposure to PS-NPs. Treatment by PS-NPs decreased root length and increased lateral root numbers. Carbon metabolism was activated (e.g., increased carbon and soluble sugar contents) whereas jasmonic acid and lignin biosynthesis were inhibited. The present study demonstrated the likelihood for transport of PS-NPs in rice roots and induced phytotoxicity by PS-NPs, which should inspire further investigations into the potential human health risks from rice consumption.
近年来，纳米塑料（NPs）对海洋生物的潜在不利影响受到了越来越多的关注。相比之下，关于陆地植物的相关数据很少，特别是关于 NPs 在植物中的运输机制以及 NPs 诱导的植物表型和分子水平上的植物毒性。为了弥补这一知识空白，我们进行了一项微宇宙研究，在这项研究中，水培培养的水稻（Oryza sativa L.）幼苗在 0、10、50 和 100 mg L 的聚苯乙烯（PS）-NPs 中暴露 16 天，并对其进行形态和生理表型以及转录组学分析。激光共聚焦扫描显微镜图证实 PS-NPs 被水稻根系吸收，这得益于水稻根系中 aquaporin 的转运活性。抗氧化酶活性的显著增强（p < 0.05）反映了水稻根系对 PS-NPs 暴露的氧化应激反应。PS-NPs 的处理减少了根长，增加了侧根数。碳代谢被激活（例如，碳和可溶性糖含量增加），而茉莉酸和木质素生物合成受到抑制。本研究表明 PS-NPs 在水稻根系中的转运可能性以及 PS-NPs 诱导的植物毒性，这应该促使进一步研究水稻消费带来的潜在人类健康风险。
