Key laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, PR China.
Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, PR China; National Key Laboratory of Rice Biology, The Advanced Seed Institute, Zhejiang University, Hangzhou 310058, PR China.
J Hazard Mater. 2023 Aug 5;455:131637. doi: 10.1016/j.jhazmat.2023.131637. Epub 2023 May 13.
Recent research has shown that polystyrene nanoplastics (PS-NPs) can inhibit plant growth and the development of crops, such as rice. In this study, we aimed to investigate the effects of PS-NPs of different particle sizes (80 nm, 200 nm, and 2 µm) and charges (negative, neutral, and positive) on rice growth, and to explore the underlying mechanisms and potential strategies for mitigating their impacts. Two-week-old rice plants were planted in a standard ½ Murashige-Skoog liquid medium holding 50 mg/L of different particle sizes and/or charged PS-NPs for 10 days, and the liquid medium without PS-NPs was used as control. The results showed that positively charged PS-NPs (80 nm PS-NH) had the greatest impact on plant growth and greatly reduced the dry biomass, root length, and plant height of rice by 41.04%, 46.34%, and 37.45%, respectively. The positively charged NPs with a size of 80 nm significantly decreased the zinc (Zn) and indole-3-acetic acid (IAA, auxin) contents by 29.54% and 48.00% in roots, and 31.15% and 64.30% in leaves, respectively, and down-regulated the relative expression level of rice IAA response and biosynthesis genes. Moreover, Zn and/or IAA supplements significantly alleviated the adverse effects of 80 nm PS-NH on rice plant growth. Exogenous Zn and/or IAA increased seedlings' growth, decreased PS-NPs distribution, maintained redox homeostasis, and improved tetrapyrrole biosynthesis in rice treated with 80 nm PS-NH. Our findings suggest that Zn and IAA synergistically alleviate positively charged NP-induced damage in rice.
最近的研究表明，聚苯乙烯纳米塑料（PS-NPs）会抑制植物生长和农作物的发育，例如水稻。在这项研究中，我们旨在探究不同粒径（80nm、200nm 和 2μm）和不同电荷（负、中、正）的 PS-NPs 对水稻生长的影响，并探索减轻其影响的潜在机制和策略。两周大的水稻幼苗被种植在含有 50mg/L 不同粒径和/或带电荷 PS-NPs 的标准 1/2 Murashige-Skoog 液体培养基中 10 天，不含 PS-NPs 的液体培养基作为对照。结果表明，带正电荷的 PS-NPs（80nm PS-NH）对植物生长的影响最大，使水稻的干生物量、根长和株高分别降低了 41.04%、46.34%和 37.45%。粒径为 80nm 的带正电荷 NPs 显著降低了根中锌（Zn）和吲哚-3-乙酸（IAA，生长素）的含量，分别降低了 29.54%和 48.00%，叶片中分别降低了 31.15%和 64.30%，并下调了水稻 IAA 响应和生物合成基因的相对表达水平。此外，Zn 和/或 IAA 补充剂显著缓解了 80nm PS-NH 对水稻植株生长的不良影响。外源性 Zn 和/或 IAA 增加了幼苗的生长，减少了 PS-NPs 的分布，维持了氧化还原平衡，并改善了 80nm PS-NH 处理的水稻中四吡咯的生物合成。我们的研究结果表明，Zn 和 IAA 协同缓解了带正电荷 NP 对水稻的损伤。
