Silver and zinc oxide nanoparticles disrupt essential parasitism, neuropeptidergic, and expansion-like proteins genes in Meloidogyneincognita

Abstract

Meloidogyne incognita leads to considerable losses in crop productivity. In this study, the impact of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) in 100, 200, or 300 ppm concentrations were investigated on some essential genes of M. incognita in vitro. For this purpose, AgNPs and ZnONPs were synthesized and characterized for their physicochemical properties. Thereafter, second-stage Juveniles (J2) of M. incognita were exposed to AgNPs and ZnONPs solution for 24 h. The LC₅₀, LC_90, and mortality rates were calculated for both nanoparticles. Finally, the expression of parasitism genes (Xyl-1; msp-20; 16D10), neuropeptidergic gene (Ace-2), expansion-like proteins (MAP-1), and oxidative stress gene (GSTS-1) was analyzed. The results showed a successful preparation of nanoparticles to obtain a pure, well-dispersed, and stable suspension, as revealed by physicochemical properties. ZnONPs showed LC₅₀ and LC₉₀ values of 63.56 and 208.5 ppm, respectively, while AgNPs recorded 11.78 and 28.59 ppm, respectively. AgNPs at concentrations 100, 200, and 300 ppm showed mortality rate 66%, 84%, and 100%, respectively, whereas ZnONPs at the same concentrations caused a 58%, 78%, and 91% mortality rate, respectively. Analysis of gene expression showed dose-dependent downregulation of each parasitism gene Xyl-1, 16D10, and msp-20 genes, neuropeptidergic gene (Ace-2), and expansion-like proteins MAP-1 after treatment with either AgNPs or ZnONPs. On the other hand, the oxidative stress response gene GSTS-1 showed upregulation with all concentrations of AgNPs and ZnONPs. The study concluded that the AgNPs and ZnONPs have efficient nematocidal activity and can be used in Meloidogyne incognita control.

Keywords: Expansion-like proteins genes; Neuropeptidergic genes; Parasitism genes; Root-knot nematode; Silver nanoparticles; Zinc oxide nanoparticles.