Nanomaterials show promising potential as agrochemical carriers, but the safety of the nanoparticles toward crops should be assessed systematically. Here, Cynodon dactylon and Brassica rapa L were used as plant models to study the phytotoxicity of halloysite nanotubes (HNTs). The effects of HNTs on the growth for two different plants were compared using the leaf spraying method. The potentially toxic effects of HNTs were assessed using higher concentrations than actual applications (0.1, 1, 10, 50, 100, 200 mg mL⁻¹). A concentration of 50 mg mL⁻¹ of HNTs will inhibit the germination of Cynodon dactylon, but the concentration of HNTs could reach 200 mg mL⁻¹ to inhibit the germination of Brassica rapa L. During a short growth period, when the concentration of HNTs is 10 mg mL⁻¹, they have a significant inhibitory effect on Brassica rapa L. However, when the concentration of HNTs exceeds 50 mg mL⁻¹, they exhibit an inhibitory effect on Cynodon dactylon. The reason for the difference between the two plants may be that under the same conditions, the larger leaf area of Brassica rapa L (broad-leaved plant) can be exposed to more HNTs. HNTs covered and blocked the plant stomata, and they can enter the plant body through the stomata. However, the Cynodon dactylon stomata was not observed from SEM results. The varied degrees of cell damage lead to different plant growth states. Therefore, HNTs are more toxic to Brassica rapa L than to Cynodon dactylon. These results provide evidence for design of nutrient and pesticide delivery systems based on HNTs.

中文翻译：

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HNT 对狗牙根和白菜两种植物的植物毒性评估


纳米材料显示出作为农用化学品载体的巨大潜力，但纳米颗粒对农作物的安全性应进行系统评估。在这里，狗牙根和白菜被用作植物模型来研究埃洛石纳米管（HNT）的植物毒性。使用叶喷法比较了 HNT 对两种不同植物生长的影响。使用比实际应用更高的浓度（0.1、1、10、50、100、200 mg mL ⁻¹ ）评估 HNT 的潜在毒性作用。 HNTs浓度为50 mg·mL ⁻¹ 时会抑制狗牙根的萌发，但HNTs浓度达到200 mg·mL ⁻¹ 时可抑制白菜的萌发。生长期较短，当HNTs浓度为10 mg·mL ⁻¹ 时，对白菜有显着的抑制作用。但当HNTs浓度超过50 mg·mL ⁻¹ ，它们对狗牙根表现出抑制作用。两种植物之间存在差异的原因可能是在相同条件下，白菜（Brassica rapa L）（阔叶植物）叶面积较大，可以接触更多的HNT。 HNTs覆盖并堵塞了植物的气孔，可以通过气孔进入植物体。然而，从SEM结果中没有观察到狗牙根的气孔。不同程度的细胞损伤导致植物生长状态不同。因此，HNT 对白菜的毒性比对狗牙根的毒性更大。这些结果为基于 HNT 的养分和农药输送系统的设计提供了证据。