Preparation of a smart nano-herbicide MP@HLDP with strong permeability performance improves herbicidal activity while reducing the adverse impacts

Abstract

Effectively increasing the herbicidal activity and utilization rate is vital for weed-sustainable management. Nanotechnology can efficiently be used to improve the utilization rate and enhance the efficacy of herbicides for advanced modern sustainable agriculture. Herein, a novel smart delivery system was developed to promote permeability performance and precision targeting of weeds for enhanced herbicidal activity. The current study designed and applied an efficient and eco-friendly nano-herbicide via metamifop (MP) modified by hydrophilic and lipophilic diblock polymer (HLDP), namely MP@HLDP. The HLDP was assembled with MP via electrostatic interaction, and the spontaneous complexation of MP with HLDP formed nearly spherical nanoparticles. The presence of HLDP reduced the contact angle of MP while increasing its retention, resulting in better foliar wettability and easier spreading of the droplets on weed leaves. Meanwhile, the plant uptake of MP@HLDP was enhanced, remarkably improving its herbicidal activity toward weed Echinochloa crus-galli (E. crusgalli), when compared to the commercial emulsion oil and technical compound even at a 30% reduced dosage. The conjoint analysis of transcriptomic and metabolome data indicated activation of the plant death responses by MP@HLDP nanoparticles through inhibiting the fatty acid biosynthesis pathway and chlorophyll metabolism. The safety evaluation of MP@HLDP nanoparticles on rice crops and systematic model nontarget organism revealed good safety to rice seedlings with reduced acute toxicity to aquatic zebrafish. Overall, new insights into creating an efficient and environmentally friendly herbicide nano-formulation were provided, promising for use in sustainable agriculture production.