Lai Mingyu, Ghouri Fozia, Sarwar Samreen, Alomrani Sarah Owdah, Riaz Muhammad, Haider Fasih Ullah, Liu Jingwen, Imran Muhammad, Ali Shafaqat, Liu Xiangdong, Shahid Muhammad Qasim
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Plant Molecular Breeding, South China Agricultural University, Guangzhou, 510642, China; College of Agriculture, South China Agricultural University, Guangzhou, 510642, China.
Department of Botany, Government College University, Faisalabad, 38000, Pakistan.
Chemosphere. 2023 Dec;345:140439. doi: 10.1016/j.chemosphere.2023.140439. Epub 2023 Oct 12.
Heavy metals, especially cadmium (Cd), cause severe toxicity symptoms in crop plants. Applying nanoparticles (NPs) as nano-fertilizers is a novel approach to mitigating plants' Cd stress. However, knowledge about the combinational use of silicon (Si) and titanium dioxide (TiO) NPs to mitigate Cd stress, especially in rice, must be highlighted. TiO-NPs (15 mg L) and Si-NPs (2.5 mM) were applied alone and in combination to rice plants grown without (control; no Cd stress) and with (100 μM) Cd concentration. Results revealed that compared to the control plants, root length, shoot length, shoot fresh weight, and root dry weight of rice seedlings were significantly decreased by 25.43%, 26.64%, 34.13%, and 29.87% under Cd exposure. However, the synergistic effect of TiO- and Si-NPs increased rice plants' shoot length, root length, root dry weight, and shoot fresh weight by 24.62%, 29.81%, 36.16%, and 33.07%, respectively, under the Cd-toxicity. The concentration of malondialdehyde (MDA) and HO were amplified due to Cd stress, which leads to damage to the subcellular structures. Si and TiO-NPs co-application improved the anti-oxidative enzymatic activities (catalase, peroxidase, superoxide dismutase) and an elevated concentration of non-enzymatic glutathione in Cd-exposed rice. The Cd accumulation was condensed by 21.37% and 19.7% in the shoot, while 48.31% and 45.65% in root tissues under Si-NPs + Cd and TiO-NPs + Cd treatments compared to Cd-alone treated seedlings, respectively. The expression patterns of metal transporters, such as OsNramp1 and OsHMA3, were the highest when rice plants were cultivated under Cd stress and significantly reduced when treated with sole and combined Si- and TiO-NPs treatments. In conclusion, combining Si- and TiO-NPs significantly improved the antioxidant enzymatic activities, chlorophyll contents, biomass production, and reduced cellular damage. Despite limitations, our findings guide future research, addressing risks, optimizing concentrations, and assessing long-term effects that can balance agricultural progress with environmental sustainability.
重金属，尤其是镉（Cd），会在农作物中引发严重的毒性症状。应用纳米颗粒（NPs）作为纳米肥料是减轻植物镉胁迫的一种新方法。然而，必须强调关于硅（Si）和二氧化钛（TiO）纳米颗粒联合使用以减轻镉胁迫的知识，尤其是在水稻中。将TiO-NPs（15毫克/升）和Si-NPs（2.5毫摩尔）单独及联合施用于在无（对照；无镉胁迫）和有（100微摩尔）镉浓度条件下生长的水稻植株。结果显示，与对照植株相比，在镉暴露下，水稻幼苗的根长、地上部长度、地上部鲜重和根干重分别显著降低了25.43%、26.64%、34.13%和29.87%。然而，在镉毒性条件下，TiO-和Si-NPs的协同效应使水稻植株的地上部长度、根长、根干重和地上部鲜重分别增加了24.62%、29.81%、36.16%和33.07%。由于镉胁迫，丙二醛（MDA）和过氧化氢（H₂O₂）的浓度增加，这导致亚细胞结构受损。Si和TiO-NPs联合施用提高了镉暴露水稻的抗氧化酶活性（过氧化氢酶、过氧化物酶、超氧化物歧化酶）以及非酶促谷胱甘肽浓度升高。与单独镉处理的幼苗相比，在Si-NPs + Cd和TiO-NPs + Cd处理下，地上部镉积累分别减少了21.37%和19.7%，根部组织中分别减少了48.31%和45.65%。金属转运蛋白如OsNramp1和OsHMA3的表达模式在镉胁迫下种植的水稻植株中最高，而在单独及联合Si-和TiO-NPs处理时显著降低。总之，Si-和TiO-NPs联合使用显著提高了抗氧化酶活性、叶绿素含量、生物量产量，并减少了细胞损伤。尽管存在局限性，但我们的研究结果为未来研究提供了指导，解决风险、优化浓度并评估可在农业发展与环境可持续性之间取得平衡的长期影响。
