Guangdong Biological Pesticide Engineering Technology Research Center, South China Agricultural University, Guangzhou, China.
College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, China.
Pest Manag Sci. 2022 Aug;78(8):3365-3375. doi: 10.1002/ps.6964. Epub 2022 May 23.
Downy mildew, a devastating disease of cucurbitaceous crops caused by Pseudoperonospora cubensis. Although a variety of fungicides are used to control downy mildew, choosing an effective product can be challenging. Environmental stimulus-responsive pesticide delivery systems have great potential to improve the effectiveness of disease and pest control and reduce the impact on environmentally beneficial organisms.
In this work, a disulfide bond (SS)-modified and chitosan oligosaccharide (COS)-capped hollow mesoporous silica (HMS) pesticide delivery system was synthesized using a hard template method for the control of downy mildew in cucurbit crops. The synthesized nanoparticles were loaded with dimethomorph (DMM), denoted as DMM@HMS-SS-COS, and the developmental toxicity of these nanoparticles to zebrafish embryos were evaluated. The results showed that the prepared DMM@HMS-SS-COS exhibited excellent dual response properties to pH and glutathione (GSH), with an encapsulation rate of up to 24.36%. DMM@HMS-SS-COS has good ultraviolet (UV) radiation stability and adhesion properties. Compared with dimethomorph suspension concentrate (SC), DMM@HMS-SS-COS was more effective against downy mildew for up to 21 days. Toxicity tests showed that DMM@HMS-SS-COS significantly reduced the effect of DMM on the hatching rate and survival rate of zebrafish embryos.
This work not only demonstrates that DMM@HMS-SS-COS could be used as a nanodelivery system for intelligent control of downy mildew but also emphasizes the necessity of increasing the acute toxicity of nanoformulations to non-target organisms in environmental risk assessment. © 2022 Society of Chemical Industry.
霜霉病是一种由古巴假霜霉菌引起的毁灭性葫芦科作物病害。虽然有多种杀菌剂可用于防治霜霉病，但选择有效的产品具有挑战性。环境刺激响应型农药输送系统在提高病虫害防治效果和降低对有益生物的环境影响方面具有巨大潜力。
本工作采用硬模板法合成了一种二硫键（SS）修饰壳聚糖寡糖（COS）封端的中空介孔硅（HMS）农药输送系统，用于防治葫芦科作物霜霉病。合成的纳米颗粒负载二甲嘧酚（DMM），记为 DMM@HMS-SS-COS，并评价了这些纳米颗粒对斑马鱼胚胎的发育毒性。结果表明，所制备的 DMM@HMS-SS-COS 对 pH 和谷胱甘肽（GSH）具有优异的双重响应特性，包封率高达 24.36%。DMM@HMS-SS-COS 具有良好的紫外线（UV）辐射稳定性和附着性能。与二甲嘧酚悬浮剂（SC）相比，DMM@HMS-SS-COS 对霜霉病的防治效果长达 21 天。毒性试验表明，DMM@HMS-SS-COS 显著降低了 DMM 对斑马鱼胚胎孵化率和存活率的影响。
本工作不仅证明了 DMM@HMS-SS-COS 可作为智能控制霜霉病的纳米输送系统，还强调了在环境风险评估中增加纳米制剂对非靶标生物的急性毒性的必要性。© 2022 英国化学学会。
