Yin Fei, Hu Lina, Li Zhenyu, Yang Xiangbing, Kendra Paul E, Hu Qiongbo
Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
College of Plant Protection, South China Agricultural University, Guangzhou, China.
Front Microbiol. 2023 Jun 2;14:1210647. doi: 10.3389/fmicb.2023.1210647. eCollection 2023.
Destruxin A (DA) is a mycotoxin isolated from the entomopathogenic fungus which has demonstrated inhibitory activity against various insect species. However, the mechanism of inhibition on target sites in insects remains unknown.
In this research, the dose-response relationship between DA and morphological changes in body tissues and organs of domestic silkworm, , were investigated by histopathological methods to identify the target sites that responded to DA.
The results showed that responses of individual tissues and organs varied with DA dosage and treatment time. At low doses (i.e., 0.01μg/g), the hemocytes were the most sensitive to DA with morphological changes apparent at 6 h after treatment. However, the muscle cells, fat body, and Malpighian tubules were unaltered. At higher doses (i.e., > 0.1μg/g), morphological changes were observed in muscle cells, fat body, and Malpighian tubules at 24 h after treatment. The results indicated that DA can be an immunosuppressant by damaging host cells like hemocytes, and at higher doses may potentially impact other physiological processes, including muscle function, metabolism, and excretion. The information presented in the current study will facilitate development of mycopesticides and novel immunosuppressants.
destruxin A（DA）是一种从昆虫病原真菌中分离出的霉菌毒素，已证明对多种昆虫具有抑制活性。然而，其对昆虫靶位点的抑制机制尚不清楚。
在本研究中，采用组织病理学方法研究了DA与家蚕（Bombyx mori）身体组织和器官形态变化之间的剂量反应关系，以确定对DA有反应的靶位点。
结果表明，各个组织和器官的反应随DA剂量和处理时间而变化。在低剂量（即0.01μg/g）下，血细胞对DA最为敏感，处理后6小时形态变化明显。然而，肌肉细胞、脂肪体和马氏管未发生改变。在较高剂量（即>0.1μg/g）下，处理后24小时在肌肉细胞、脂肪体和马氏管中观察到形态变化。结果表明，DA可能通过损伤血细胞等宿主细胞而成为一种免疫抑制剂，并在较高剂量下可能影响其他生理过程，包括肌肉功能、代谢和排泄。本研究提供的信息将有助于开发杀真菌剂和新型免疫抑制剂。
