Plant-parasitic nematodes are considered one of the most crop-distractive pests that attack plants (Heflish et al., 2021). Root-knot nematodes (RKN) (Meloidogyne spp.) are species threatening almost all horticultural and economic crops (Tauseef et al., 2021). The vulnerability of the RKN resulted in growth reduction, quality, yield deficiency, diminished resistance to biotic and abiotic stresses, and even complete crop loss in severe invasions (Tapia-Vázquez et al., 2022). Under favorable environments, infected juveniles (J2s) hatch out of eggs and locate plant roots via the detection of secondary root metabolites that modulate the expression of about 21 neuropeptide genes in root-knot nematodes such as Ace-2 (Petitot et al., 2020). Then RKN expresses many cell wall-degrading enzymes, such as xylanase enzyme (encoded Mi-XYL1), to enter the plant roots through the root tip (Mitreva-Dautova et al., 2006). Inside plant cells, parasitic J2s reach root meristem through intercellular spaces (Jagdale et al., 2021) by secretion of an expansion-like protein encoded by a MAP-1 gene (Shukla et al., 2018). At this point, they form giant cells by the action of effectors secreted from the esophageal glands (Shi et al., 2018). These effectors activate plant immune responses to protect themselves by producing reactive oxygen species (Sato et al., 2019a). However, RKN expresses oxidative stress response gene glutathione S-transferases (GSTS-1) to protect itself (Carneiro et al., 2015).

Chemicals are used as a management tactic to reduce the nematode effect; however, these chemicals are highly lethal to humanity and environmental health (Heflish et al., 2021; Abd-Elgawad, 2021). Biological control is proposed as a management approach with many benefits, such as sustainability, cost-effectiveness, environmental safety, and energy self-sufficiency. However, it has some concerns, including host interaction, the date of harvesting in controlling root galling, and the number of eggs/egg mass (Shahid et al., 2022). Additionally, RNA interference (RNAi) is a recent management strategy for RNK infection (Whitten et al., 2016). It includes expressing dsRNA complementary to nematode genes in transgenic plants or direct molecules ingestion by oral administration (Banerjee et al., 2017). However, this technology required high enrichment genomic databases due to the high sequence conservation with other kingdoms, such as plants and animals (Iqbal et al., 2021). Also, exposing non-target organisms to plant parts or debris of genetically modified plants through RNAi is possible. Therefore, new nematocidal active ingredients are required to combat this challenge.

In the recent past, metallic nanoparticles (MNPs) have been considered promising materials because they have interesting properties that differ from their bulk form (Vodnik et al., 2019). The main feature of nanoparticles is the high surface area to volume ratio, allowing the nanostructure to be widely used in many areas, including biotechnology, medicine, environmental remediation, agriculture, and the food industry (Shnoudeh et al., 2019). In addition, MNPs are easily obtained via chemical, physical and biological methods (Rajabi et al., 2017, 2020; Jamkhande et al., 2019; Saudi et al., 2022). In agriculture, nanoparticles promote plant growth, reduce disease severity, increase crop production, and inhibit pathogenic infections (Dam et al., 2022). AgNPs and ZnONPs are prominent examples of nanomaterials being applied to control plant pathogens (Khan et al., 2021a). Furthermore, AgNPs and ZnONPs have shown evidence of being potentially effective nematicides (Kalaba et al., 2021; Barbosa et al., 2019), and their toxicity is associated with the induction of oxidative stress in the cells of targeted nematodes (Ghareeb et al., 2022). So far, to our knowledge, the molecular response of M. incognita due to MNPs exposure is not fully described. The current study tried to uncover this point by monitoring gene expression analysis of effectors, expansion, neuropeptidergic, and oxidative stress response genes after treatment with either AgNPs or ZnONPs.