通过减轻镉毒性的虾青素纳米颗粒改善小麦幼苗的形态生理、超微结构和营养状况,Journal of Hazardous Materials

耕地和水体中的重金属积累已成为众多粮食安全挑战中的严重全球性问题之一。特别是环境中的镉 (Cd) 浓度大幅增加，对重要农作物，尤其是小麦 ( Triticum aestivum ) 的生长和产量产生负面影响L.)。毫无疑问，纳米技术是一门革命性的科学，但对纳米粒子-植物相互作用及其对金属应力的潜在缓解作用的理解仍然难以捉摸。在这里，我们研究了虾青素纳米颗粒 (AstNPs) 在 Cd 胁迫改善中的机制作用及其在 Cd 加标条件下与小麦的相互作用。通过紫外可见光谱证实了 AstNPs 的制造，其中颗粒在 423  nm 处显示出特征峰。然而，傅里叶变换红外、X 射线衍射、扫描电子显微镜和透射电子显微镜分析证实，在 12.03-30.37 nm 的尺寸范围内存在稳定的 AstNPs 球形纳米晶体 。AstNPs 的水培应用 (100  mg  L-1 ) 与未处理的受镉影响的幼苗相比，受镉影响的小麦植物的枝条高度（59%）、枝条干重（31%）、氮浓度（42%）和磷浓度（26%）增加。此外，与仅用 Cd 处理的植物相比，AstNPs 处理的植物显示出顶叶 Cd 易位减少 (29%)。在添加 Cd 的条件下，与未经处理的植物相比，经 AstNPs 处理的植物表现出改善的营养成分（P、N、K +和 Ca 2+ ），其中 Na +含量相对降低。有趣的是，发现 AstNPs 通过负调控 Cd 转运蛋白基因（TaHMA2和TaHMA3)，并通过触发TaSOD和TaPOD基因的表达激活抗氧化机制来缓解植物的氧化爆发。因此，观察到 AstNPs 的应用有助于维持受 Cd 影响的小麦植物的养分获取和离子稳态，从而改善 Cd 胁迫下植物的理化特征。这项研究表明，AstNPs 似乎可以作为重金属污染环境下植物的应激稳定剂。

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Heavy metal accumulation in arable land and water bodies has become one of the serious global issues among multitude of food security challenges. In particular, cadmium (Cd) concentration has been increasing substantially in the environment that negatively affects the growth and yield of important agricultural crops, especially wheat (Triticum aestivum L.). No doubt, nanotechnology is a revolutionary science but the comprehension of nanoparticle-plants interaction and its potential alleviatory role against metal stress is still elusive. Here, we investigated the mechanistic role of astaxanthin nanoparticles (AstNPs) in Cd stress amelioration and their interaction with wheat under Cd-spiked conditions. The AstNPs fabrication was confirmed through ultraviolet visible spectroscopy, where the particles showed characteristic peak at 423 nm. However, Fourier transform infrared, X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses confirmed the presence of stabilized spherical-shaped nanocrystals of AstNPs within the size range of 12.03-30.37 nm. The hydroponic application of AstNPs (100 mg L−1) to Cd-affected wheat plants increased shoot height (59%), shoot dry weight (31%), nitrogen concentration (42%), and phosphorus concentration (26%) as compared to non-treated Cd affected seedlings. Moreover, AstNPs-treated plants showed reduction in acropetal Cd translocation (29%) in contrast to plants treated with Cd only. Under Cd-spiked conditions, AstNPs-treated plants displayed an improved nutrient profile (P, N, K+ and Ca2+) with a relative decrease in Na+ content in comparison with non-treated plants. Interestingly, it was found that AstNPs restricted the translocation of Cd to aerial plant parts by negatively regulating Cd transporter genes (TaHMA2 and TaHMA3), and relieved plants from oxidative burst by activating antioxidant machinery via triggering expressions of TaSOD and TaPOD genes. Consequently, it was observed that the application of AstNPs helped in maintaining the nutrient acquisition and ionic homeostasis in Cd-affected wheat plants, which subsequently improved the physiochemical profiles of plants under Cd-stress. This study suggests that AstNPs plausibly serve as stress stabilizers for plants under heavy metal-polluted environment.