Sun Cheng, Zhao Chen, Wang Guohua, Han Rong
College of Chemistry and Materials Science, Shanxi Normal University, Taiyuan, 030000, China.
Shanxi Provincial Key Laboratory of Plant Macromolecular Adversity Response, Shanxi Normal University, Taiyuan, 030000, China.
Protoplasma. 2025 Feb 5. doi: 10.1007/s00709-025-02038-0.
Cerium oxide nanoparticles (CeO-NPs) have been widely applied worldwide. In the field of agriculture, they have gained attention for their ability to promote seed germination, root elongation, and biomass accumulation in plants, as well as to increase plant resistance to various abiotic stresses. However, the underlying molecular mechanisms remain to be elucidated. Limited research has been conducted on whether CeO-NPs can help plants mitigate damage caused by UV-B stress. In this study, Arabidopsis thaliana was selected as the research subject to investigate the effects of CeO-NPs on the resistance of plant roots to UV-B stress at both the physiological and molecular levels. Our findings demonstrated that 120 mg/mL CeO-NPs significantly alleviated UV-B-induced damage to the root system of Arabidopsis thaliana. Specifically, CeO-NPs increased the activities of the root tip antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), reducing oxidative stress. The results from GUS staining and GFP fluorescence assays conducted on the transgenic lines CYCB1;1-GUS, DR5-GUS, QC25-GUS, and WOX5-GFP indicated that CeO-NPs could increase the cell division activity, auxin accumulation, and stem cell niche activity of Arabidopsis thaliana root tips under UV-B stress. Furthermore, observations of GFP fluorescence in the transgenic lines PIN1-GFP, PIN2-GFP, and PIN7-GFP revealed that CeO-NPs promoted root growth by inducing the accumulation of auxin transporters. Quantitative real-time PCR (qRT-PCR) analysis revealed that under UV-B stress, CeO-NPs upregulated the expression of genes related to antioxidant enzymes, the cell cycle and auxin biosynthesis-related genes in Arabidopsis thaliana root tips while downregulating the expression of genes related to DNA damage repair and stress response. Therefore, CeO-NPs have potential value for promoting plant growth and mitigating UV-B stress.
氧化铈纳米颗粒（CeO-NPs）已在全球范围内得到广泛应用。在农业领域，它们因其能够促进植物种子萌发、根系伸长和生物量积累，以及增强植物对各种非生物胁迫的抗性而受到关注。然而，其潜在的分子机制仍有待阐明。关于CeO-NPs是否能帮助植物减轻UV-B胁迫造成的损害，相关研究较少。在本研究中，选择拟南芥作为研究对象，从生理和分子水平研究CeO-NPs对植物根系抗UV-B胁迫的影响。我们的研究结果表明，120 mg/mL的CeO-NPs显著减轻了UV-B对拟南芥根系系统的损伤。具体而言，CeO-NPs提高了根尖抗氧化酶超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性，减轻了氧化应激。对转基因株系CYCB1;1-GUS、DR5-GUS、QC25-GUS和WOX5-GFP进行的GUS染色和GFP荧光分析结果表明，CeO-NPs可以在UV-B胁迫下提高拟南芥根尖的细胞分裂活性、生长素积累和干细胞龛活性。此外，对转基因株系PIN1-GFP、PIN2-GFP和PIN7-GFP的GFP荧光观察表明，CeO-NPs通过诱导生长素转运体的积累促进根系生长。定量实时PCR（qRT-PCR）分析表明，在UV-B胁迫下，CeO-NPs上调了拟南芥根尖中与抗氧化酶、细胞周期和生长素生物合成相关基因的表达，同时下调了与DNA损伤修复和应激反应相关基因的表达。因此，CeO-NPs在促进植物生长和减轻UV-B胁迫方面具有潜在价值。
