The development of efficient and environmentally friendly plant protection systems is one of the major challenges for a sustainable agriculture of the future. Citrus canker caused by the pathogen Xanthomonas citri subsp. citri (X. citri) affects all cultivated citrus species worldwide and is responsible for enormous economic losses and restrictions in international trade. Currently used commercial copper-based formulations are the origin of contamination for soil and groundwater, affecting local ecosystems and human health. A copper-free sustainable microgel-based plant protection system able to efficiently combat X. citri is developed. Microgels decorated with anchor peptides exhibit strong non-covalent attachment to the surface of orange leaves and have the ability to release hexyl gallate, which inhibits the growth and spreading of pathogens. The tailored design of the microgel network allows high loadings of hexyl gallate (up to 40 wt.%) and a controlled release of gallates from microgels that provide long-term protection. The antibacterial activity of the hexyl gallate-loaded microgels is demonstrated by various in vitro assays as well as on orange plants in greenhouse settings. The experimental results suggest that the developed sustainable microgel-based plant protection system for citrus trees allows efficient abatement of X. citri and reduces environmental pollution caused by copper formulations.

中文翻译：

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没食子酸己酯负载的微凝胶可有效预防柑橘溃疡病

开发高效、环保的植物保护系统是未来可持续农业的主要挑战之一。由病原体柑橘黄单胞菌亚种引起的柑橘溃疡病。柑橘( X .  citri ) 影响全世界所有栽培的柑橘品种，并造成巨大的经济损失和国际贸易的限制。目前使用的商业铜基制剂是土壤和地下水污染的根源，影响当地生态系统和人类健康。开发了一种基于微凝胶的无铜可持续植物保护系统，能够有效对抗柑橘小叶枯病菌。锚定肽修饰的微凝胶在橙叶表面表现出很强的非共价附着力，并具有释放没食子酸己酯的能力，从而抑制病原体的生长和传播。微凝胶网络的定制设计允许高含量没食子酸己酯（高达 40 wt.%），并从微凝胶中控制释放没食子酸酯，从而提供长期保护。各种体外试验以及温室环境中的橙色植物都证明了负载没食子酸己酯的微凝胶的抗菌活性。实验结果表明，所开发的可持续的基于微凝胶的柑橘树植物保护系统可以有效地消除柑橘腐病菌，并减少铜制剂造成的环境污染。