Industrial Crops Institute, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266100, China.
Genes (Basel). 2024 Sep 29;15(10):1279. doi: 10.3390/genes15101279.
BACKGROUND/OBJECTIVES: The utilization of methyl-thiophanate (MT) in vegetables and fruits is widespread due to its broad efficiency, yet its potential impact on silkworm growth remains uncertain. This study aims to examine the effects of MT on the growth of silkworms. Specifically, we assessed the weights of fifth-instar larvae that were fed mulberry leaves saturated with three concentrations (2.5, 5, and 10 mg/mL) of MT, as well as the weights of a control group.
TEM was used to show the status of the silkworm midgut after MT supplementation. Oxidative stress was evaluated in the presence of MT. Furthermore, a transcriptomic sequencing experiment was conducted to investigate the mechanism through which the development of silkworms is induced by MT.
Our findings indicate that the supplementation of MT hindered larval growth compared to the control group, suggesting a toxic effect of MT on silkworms. The transmission electron microscopy (TEM) results show that MT supplementation induced autophagy in the silkworm midgut. MT was also found to induce oxidative stress in silkworms through the activation of reactive oxygen (ROS), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities. Subsequent transcriptomic analysis revealed 1265 significantly differentially expressed genes (DEGs) in response to MT. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that these DEGs were associated with antioxidant defense, detoxification processes, lysosome biogenesis, and metabolic pathways.
These findings suggest that MT toxicity in silkworm larvae is mediated through the induction of oxidative stress and alterations in metabolism. This study contributes to our understanding of the impacts of MT exposure on silkworms and provides insights into potential pesticides for use in mulberry gardens.
背景/目的：甲基硫环磷（MT）因其广泛的效率而在蔬菜和水果中广泛使用，但它对家蚕生长的潜在影响尚不确定。本研究旨在研究 MT 对家蚕生长的影响。具体而言，我们评估了喂食三种浓度（2.5、5 和 10 mg/mL）MT 饱和的桑叶的五龄幼虫的体重，以及对照组的体重。
TEM 用于显示 MT 补充后家蚕中肠的状态。评估 MT 存在下的氧化应激。此外，进行了转录组测序实验，以研究 MT 诱导家蚕发育的机制。
我们的研究结果表明，与对照组相比，MT 的补充抑制了幼虫的生长，表明 MT 对家蚕具有毒性作用。透射电子显微镜（TEM）结果表明，MT 补充诱导了家蚕中肠的自噬。通过激活活性氧（ROS）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性，MT 还被发现在家蚕中诱导氧化应激。随后的转录组分析显示，MT 诱导了 1265 个显著差异表达基因（DEGs）。京都基因与基因组百科全书（KEGG）分析表明，这些 DEGs与抗氧化防御、解毒过程、溶酶体生物发生和代谢途径有关。
这些发现表明，MT 对家蚕幼虫的毒性是通过诱导氧化应激和代谢改变介导的。本研究有助于我们了解 MT 暴露对家蚕的影响，并为桑树园潜在的农药提供了见解。
