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Using a simple one-pot method, we developed a prochloraz (Pro) and pH-jump reagent-loaded zeolitic imidazolate framework-8 (PD@ZIF-8) composite for the smart control of Sclerotinia disease. The pH-jump reagent can induce the acidic degradation of ZIF-8 using UV light to realize the controlled release of Pro. Thus, the physical properties of PD@ZIF-8, such as its release, formulation stability, and adhesion, were investigated in detail. The results showed that the quantity of Pro released by PD@ZIF-8 under UV light irradiation (365 nm) was 63.4 ± 3.5%, whereas under dark conditions, it was only 13.7 ± 0.8%. In vitro activity indicated that the EC50 of PD@ZIF-8 under UV light irradiation was 0.122 ± 0.02 μg/mL, which was not significantly different from that of Pro (0.107 ± 0.01 μg/mL). Pot experiments showed that the efficacy of PD@ZIF-8 under light irradiation was 51.2 ± 5.7% for a fungal infection at 14 days post-spraying, whereas the effectiveness of prochloraz emulsion in water was only 9.3 ± 3.3%. Furthermore, fluorescence tracking of ZIF-8 and biosafety experiments showed that ZIF-8 could be absorbed by plant leaves and transported to various parts of oilseed rape in a short period of time and that PD@ZIF-8 was relatively safe for plants and HepG2 cells. These results highlight the potential of the composite to provide efficient and smart delivery of fungicides into plants for protection against diseases and provide an idea for developing sustainable agriculture.

Avermectin (AVM) as a nonsystemic pesticide possesses a low effective utilization rate. Studies of the multifunctional pesticide delivery system for improving biological activity are developing prosperously. In this study, multifunctional avermectin/polysuccinimide with glycine methyl ester nanoparticles (AVM-PGA) were prepared by the selfassembly process. The AVM loading capacity was up to 23.7%. After 24 h of UV irradiation, there was still about 70% of AVM remaining in PGA 42 nanocarriers, as opposed to less than 5% of the free-form AVM. The rising ambient pH promoted the release of AVM using an in vitro releasing test, revealing a favorable pH-responsively controlled-release property. The mortality rate of Plutella xylostella with 2.5 μg/mL of AVM content of AVM-PGA 42 was 96.3% after 48 h, while that of free AVM was only 51.5%. In addition, the AVM could be detected in stems and all leaves treated with AVM-PGA 42 nanoparticles, whereas rare AVM was detected only in treated leaves for the free-form AVM, which achieved the transportation of nanocarriers carrying AVM in rice for the first time. Furthermore, the PGA nanoparticles performed a good growth promoting effect on rice. These results show that the AVM-PGA 42 nanopesticides have a great potential application prospect to control the pest and improve the drug utilization efficiency on agriculture.

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Developing an effective and safe technology to control severe bacterial diseases in agriculture has attracted significant attention. Here, ZnO nanosphere and ZIF-8 are employed as core and shell, respectively, and then a pH-responsive core–shell nanocarrier (ZnO-Z) was prepared by in situ crystal growth strategy. The bactericide berberine (Ber) was further loaded to form Ber-loaded ZnO-Z (Ber@ZnO-Z) for control of tomato bacterial wilt disease. Results demonstrated that Ber@ZnO-Z could release Ber rapidly in an acidic environment, which corresponded to the pH of the soil where the tomato bacterial wilt disease often outbreak. In vitro experiments showed that the antibacterial activity of Ber@ZnO-Z was about 4.5 times and 1.8 times higher than that of Ber and ZnO-Z, respectively. It was because Ber@ZnO-Z could induce ROS generation, resulting in DNA damage, cytoplasm leakage, and membrane permeability changes so the released Ber without penetrability more easily penetrated the bacteria to achieve an efficient synergistic bactericidal effect with ZnO-Z carriers after combining with DNA. Pot experiments also showed that Ber@ZnO-Z significantly reduced disease severity with a wilt index of 45.8% on day 14 after inoculation, compared to 94.4% for the commercial berberine aqueous solution. More importantly, ZnO-Z carriers did not accumulate in aboveground parts of plants and did not affect plant growth in a short period. This work provides guidance for the effective control of soil-borne bacterial diseases and the development of sustainable agriculture.

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