Preparation of Multifunctional Nano-Protectants for High-Efficiency Green Control of Anthracnose

Nanomaterials cannot only act as active ingredients (AIs), but also adjuvants to encapsulate or attach AIs to improve their fungicidal activity. Herein, a hydrophilic and lipophilic diblock polymer (HLDP) is designed and synthesized to prepare a series of HLDP nano-protectants to explore the best HLDP nano-protectant for anthracnose management. These results demonstrate that the HLDP-CS nano-protectant displays the best control effects on mango anthracnose via the direct pathogen inhibition and amplified plant immune responses. The HLDP can be spontaneously conjugated with CS into nanoscale spherical particles through hydrophobic interaction. The complexation of CS with HLDP remarkably improves the deposition and adhesion of CS droplets on mango leaves. The HLDP can interact with mycelium via electrostatic interaction to damage the cell wall/membrane, which can act as an AI to directly suppress the spore germination and mycelial growth. Meanwhile, HLDP can be applied as an adjuvant for CS to amplify the plant immune responses via accelerating the biosynthesis of secondary metabolites and plant hormones. This work reports the multiple missions for nanomaterials in pathogen control, which proposes a novel strategy for designing nano-protectant with dual-synergistic mechanism.