Meloidogyne incognita is a destructive and economically important agricultural pest. Similar to other plant-parasitic nematodes, management of M. incognita relies heavily on chemical controls. As old, broad spectrum, and toxic nematicides leave the market, replacements have entered including fluensulfone, fluazaindolizine, and fluopyram that are plant-parasitic nematode specific in target and less toxic to applicators. However, there is limited research into their modes-of-action and other off-target cellular effects caused by these nematicides in plant-parasitic nematodes. This study aimed to broaden the knowledge about these new nematicides by examining the transcriptional changes in M. incognita second-stage juveniles (J2) after 24-h exposure to fluensulfone, fluazaindolizine, and fluopyram as well as oxamyl, an older non-fumigant nematicide. Total RNA was extracted and sequenced using Illumina HiSeq to investigate transcriptional changes in the citric acid cycle, the glyoxylate pathway, \(\upbeta\)-fatty acid oxidation pathway, oxidative phosphorylation, and acetylcholine neuron components. Observed transcriptional changes in M. incognita exposed to fluopyram and oxamyl corresponded to their respective modes-of-action. Potential targets for fluensulfone and fluazaindolizine were identified in the \(\upbeta\)-fatty acid oxidation pathway and 2-oxoglutarate dehydrogenase of the citric acid cycle, respectively. This study provides a foundation for understanding how potential nematicide resistance could develop, identifies cellular pathways as potential nematicide targets, and determines targets for confirming unknown modes-of-action.

南方根结线虫是一种具有破坏性且具有重要经济意义的农业害虫。与其他植物寄生线虫类似，南方根结线虫的管理在很大程度上依赖于化学控制。随着旧的、广谱的、有毒的杀线虫剂退出市场，替代品已经进入市场，包括氟烯磺、氟氮杂吲嗪和氟吡菌酰胺，它们是针对植物寄生线虫的特异性药物，并且对施药者的毒性较小。然而，关于这些杀线虫剂在植物寄生线虫中的作用模式和其他脱靶细胞效应的研究有限。本研究旨在通过检查南方根结线虫第二阶段幼虫 (J2) 在暴露于氟烯磺、氟氮吲嗪、氟吡菌胺以及草霉灵（一种较老的非熏蒸杀线虫剂） 24 小时后的转录变化，扩大对这些新型杀线虫剂的了解。 。提取总 RNA 并使用 Illumina HiSeq 进行测序，以研究柠檬酸循环、乙醛酸途径、 \(\upbeta\)-脂肪酸氧化途径、氧化磷酸化和乙酰胆碱神经元成分的转录变化。在暴露于氟吡菌酰胺和草酰胺的南方根结线虫中观察到的转录变化与其各自的作用模式相对应。分别在柠檬酸循环的\(\upbeta\)-脂肪酸氧化途径和2-酮戊二酸脱氢酶中鉴定出fluensulfone和fluazaindolizine的潜在靶标。这项研究为了解潜在的杀线虫剂抗性如何发展、确定细胞途径作为潜在的杀线虫剂靶标以及确定用于确认未知作用模式的靶标奠定了基础。