Zein and resveratrol Schiff base nanocomplexes: An efficient delivery system to enhance the antibacterial efficacy of berberine.

Plant-derived bactericides with limited drug resistance and environmental friendliness are promising alternatives to traditional chemical bactericides. Berberine (BBR) is a natural product with excellent biological activity against bacteria. Novel pesticide delivery systems were designed and constructed based on the plant-derived zein resveratrol (RSV) and its derivative 4-((E)-((2-hydroxyphenyl)imino)methyl)-5-((E)-4-hydroxystyryl)benzene-1,3-diol (XF) to improve the efficacy of BBR. BBR@Zein-RSV and BBR@Zein-XF nanoparticles (NPs) had uniform dispersion and were approximately 119.19 and 86.82 nm, with encapsulation rates of 55.71 % and 83.34 %, respectively. BBR@Zein-RSV and BBR@Zein-XF NPs used dual pH and redox reaction mechanisms to achieve a controlled release into the environment. Especially, BBR@Zein-XF NPs exhibited antibacterial activity against Xanthomonas oryzae pv. oryzicola with an EC50 value of 0.98 mg/L. Additionally, it showed excellent protective (51.52 %) and curative (48.17 %) effects against rice bacterial leaf streaks. NPs could inhibit biofilm formation and extracellular polysaccharide production but promote reactive oxygen species levels, thereby destroying the integrity of bacteria and eventually leading to cell death. Proteomic analysis revealed that BBR@Zein-XF NPs regulated the expression of phosphoenolpyruvate carboxykinase and lactoylglutathione lyase, thereby influencing plant growth, energy metabolism, and maintaining a normal redox state. This study provides new ideas for extensively utilizing plant-derived antibacterial agents by developing innovative and eco-friendly nano-pesticides.