Abstract

Trichlorfon (TCF), an organophosphorus pesticide, has long been used in agriculture as an insecticide for crop protection. However, its residual presence has caused significant economic losses to the sericulture industry, hindering the development of Bombyx mori ( B . mori ) farming. Although previous studies have investigated the toxicity of TCF to silkworms, the detailed toxic effects and molecular mechanisms remain poorly understood. In this study, the potential molecular targets and mechanisms of TCF-induced injury in silkworms were investigated in vivo and in vitro by combining RNA sequencing, qRT-PCR and other techniques. It is found that TCF exposure leads to damage of growth and development in silkworms, as evidenced by reduced body weight, increased mortality, and decline of cluster, cocooning, pupation and egg production. Further RNA sequencing analysis identified several differentially expressed genes, particularly LOC101744260 , as well as altered pathways, notably the glutamine metabolism pathway—both of which are closely associated with ferroptosis. In vivo and in vitro experiments have confirmed that the expression levels of ferroptosis-related genes, including Fer HCH , Fer 2LCH , Keap1 , Tf , Gtpx and SOD1 exhibited significant changes in expression levels. These changes are accompanied by elevated intracellular Fe 2+ and Fe 3+ levels and oxidative stress. Moreover, N-acetylcysteine (NAC) treatment partially reverses TCF-induced growth and developmental impairments at the individual and cellular levels. Taken together, these results indicate for the first time that TCF exposure induces damage of growth and development in silkworms by activating the ferroptosis pathway. This study provides a new insight into the toxic mechanisms of TCF in silkworms and offers a theoretical basis for the prevention and control of pesticide pollution in silkworms industry.