PDF(Pubmed)
Abstract：
Arsenic (As) is a heavy metal that is toxic to both plants and animals. Silicon nanoparticles (SiNPs) can alleviate the detrimental effects of heavy metals on plants, but the underlying mechanisms remain unclear. The study aims to synthesize SiNPs and reveal how they promote plant health in Arsenic-polluted soil. 0 and 100% v/v SiNPs were applied to soil, and Arsenic 0 and 3.2 g/ml were applied twice. Maize growth was monitored until maturity. Small, irregular, spherical, smooth, and non-agglomerated SiNPs with a peak absorbance of 400 nm were synthesized from Pycreus polystachyos. The SiNPs (100%) assisted in the development of a deep, prolific root structure that aided hydraulic conductance and gave mechanical support to the maize plant under As stress. Thus, there was a 40-50% increase in growth, tripled yield weights, and accelerated flowering, fruiting, and senescence. SiNPs caused immobilization (As(III)=SiNPs) of As in the soil and induced root exudates Phytochelatins (PCs) (desGly-PC2 and Oxidized Glutathione) which may lead to formation of SiNPs=As(III)-PCs complexes and sequestration of As in the plant biomass. Moreover, SiNPs may alleviate Arsenic stress by serving as co-enzymes that activate the antioxidant-defensive mechanisms of the shoot and root. Thus, above 70%, most reactive ROS (OH) were scavenged, which was evident in the reduced MDA content that strengthened the plasma membrane to support selective ion absorption of SiNPs in place of Arsenic. We conclude that SiNPs can alleviate As stress through sequestration with PCs, improve root hydraulic conductance, antioxidant activity, and membrane stability in maize plants, and could be a potential tool to promote heavy metal stress resilience in the field.
摘要：
砷（As）是一种重金属，对植物和动物都有毒。硅纳米粒子（SiNPs）可以减轻重金属对植物的有害影响，但潜在的机制仍不清楚。该研究旨在合成SiNPs，并揭示它们如何促进砷污染土壤中的植物健康。0和100%v/vSiNPs施用于土壤，和砷0和3.2g/ml施用两次。监测玉米生长直至成熟。小,不规则,球形,光滑,从Pycreuspolystachyos合成了峰值吸光度为400nm的非团聚SiNPs。SiNPs(100%)协助开发了一个深层的，丰富的根系结构有助于水力传导，并为As胁迫下的玉米植株提供机械支持。因此，有40-50%的增长，产量重量增加了两倍，加速开花，结果，和衰老。SiNPs导致土壤中As的固定（As（III）=SiNPs），并诱导根系分泌物植物螯合肽（PC）（desGly-PC2和氧化谷胱甘肽），这可能导致SiNPs=As（III）-PCs复合物的形成和As在植物生物量中的螯合。此外，SiNP可以通过充当激活芽和根的抗氧化防御机制的辅酶来减轻砷胁迫。因此，70%以上,大多数反应性ROS（OH）被清除，这在减少的MDA含量中很明显，这增强了质膜以支持SiNPs代替砷的选择性离子吸收。我们得出的结论是，SiNPs可以通过与PC隔离来缓解As压力，提高根部导水率，抗氧化活性，和玉米植株的膜稳定性，并可能成为在该领域促进重金属应力恢复能力的潜在工具。
