Enzyme-Responsive Lignin Nanocarriers for Triggered Delivery of Abamectin to Control Plant Root-Knot Nematodes (Meloidogyne incognita)

Abstract

Intelligently responsive nanoparticles can improve insecticidal activity against target organisms and reduce the use of pesticides in agriculture. In this study, enzymatic hydrolysis lignin (EHL) nanocarriers with enzyme responsiveness were successfully prepared by electrostatic interaction, and abamectin (Abm)-loaded EHL-based nanoparticles (Abm@L-CL) were investigated. The release behavior of Abm@L-CL nanoparticles showed that Abm was released rapidly in the presence of cellulase and pectinase but slowly under natural conditions. The insecticidal activity of Abm@L-CL treatment (LC50 = 0.68 μg/mL) against nematodes (Meloidogyne incognita) was significantly more effective than that of original Abm treatment (LC50 = 1.32 μg/mL). The mortality rate of Abm@L-CL was more than 90% by applying the same dose of Abm after 12 h. The bioactivity of Abm@L-CL against root-knot nematodes was 1.7-fold greater than that of Abm. The result of fluorescence indicated that nanoparticles could enter the intestinal tract through the oral cavity of nematodes and achieve obvious gastric toxicity. Furthermore, the enzyme-controlled lignin-based Abm nanocarriers could penetrate the tomato root near the elongation zone. This study provided intelligent enzyme-responsive nanocarriers for efficient management of soil-borne diseases and pests in green agricultural inputs.