Hussain Mujahid, Kaousar Rehana, Haq Syed Ijaz Ul, Shan Changfeng, Wang Guobin, Rafique Nadia, Shizhou Wang, Lan Yubin
College of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, Shandong, China.
National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology (NPAAC), Ministry of Science and Technology, College of Electronics Engineering, South China Agricultural University, Guangzhou, China.
Front Plant Sci. 2024 Jan 18;15:1346427. doi: 10.3389/fpls.2024.1346427. eCollection 2024.
Cadmium stress is a major threat to plant growth and survival worldwide. The current study aims to green synthesis, characterization, and application of zinc-oxide nanoparticles to alleviate cadmium stress in maize ( L.) plants. In this experiment, two cadmium levels (0, 0.6 mM) were applied to check the impact on plant growth attributes, chlorophyll contents, and concentration of various primary metabolites and antioxidants under exogenous treatment of zinc-oxide nanoparticles (25 and 50 mg L) in maize seedlings. Tissue sampling was made 21 days after the zinc-oxide nanoparticles application. Our results showed that applying cadmium significantly reduced total chlorophyll and carotenoid contents by 52.87% and 23.31% compared to non-stress. In comparison, it was increased by 53.23%, 68.49% and 9.73%, 37.53% with zinc-oxide nanoparticles 25, 50 mg L application compared with cadmium stress conditions, respectively. At the same time, proline, superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase contents were enhanced in plants treated with cadmium compared to non-treated plants with no foliar application, while it was increased by 12.99 and 23.09%, 23.52 and 35.12%, 27.53 and 36.43%, 14.19 and 24.46%, 14.64 and 37.68% by applying 25 and 50 mg L of zinc-oxide nanoparticles dosages, respectively. In addition, cadmium toxicity also enhanced stress indicators such as malondialdehyde, hydrogen peroxide, and non-enzymatic antioxidants in plant leaves. Overall, the exogenous application of zinc-oxide nanoparticles (25 and 50 mg L) significantly alleviated cadmium toxicity in maize. It provides the first evidence that zinc-oxide nanoparticles 25 ~ 50 mg L can be a candidate agricultural strategy for mitigating cadmium stress in cadmium-polluted soils for safe agriculture practice.
镉胁迫是全球范围内植物生长和生存面临的主要威胁。当前研究旨在进行氧化锌纳米颗粒的绿色合成、表征及其在缓解玉米植株镉胁迫方面的应用。在本实验中，设置了两个镉水平（0、0.6 mM），以检测在玉米幼苗中施加氧化锌纳米颗粒（25和50 mg/L）的外源处理下，对植物生长特性、叶绿素含量以及各种初级代谢产物和抗氧化剂浓度的影响。在施加氧化锌纳米颗粒21天后进行组织采样。我们的结果表明，与无胁迫相比，施加镉显著降低了总叶绿素和类胡萝卜素含量，分别降低了52.87%和23.31%。相比之下，与镉胁迫条件相比，施加25、50 mg/L的氧化锌纳米颗粒分别使叶绿素和类胡萝卜素含量提高了53.23%、68.49%以及9.73%、37.53%。同时，与未进行叶面喷施处理的植株相比，镉处理的植株中脯氨酸、超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过氧化物酶含量增加，而分别施加25和50 mg/L的氧化锌纳米颗粒剂量后，这些物质的含量分别增加了12.99%和23.09%、23.52%和35.12%、27.53%和36.43%、14.19%和24.46%、14.64%和37.68%。此外，镉毒性还增强了植物叶片中的胁迫指标，如丙二醛、过氧化氢和非酶抗氧化剂。总体而言，外源施加氧化锌纳米颗粒（25和50 mg/L）显著缓解了玉米中的镉毒性。这首次证明了25~50 mg/L的氧化锌纳米颗粒可作为一种农业策略，用于减轻镉污染土壤中的镉胁迫，以实现安全的农业生产实践。
