Plant and insect virus-like particles: emerging nanoparticles for agricultural pest management.

Virus-like particles (VLPs) represent a biodegradable, biocompatible nanomaterial made from viral coat proteins that can improve the delivery of antigens, drugs, nucleic acids, and other substances, with most applications in human and veterinary medicine. Regarding agricultural viruses, many insect and plant virus coat proteins have been shown to assemble into VLPs accurately. In addition, some plant virus-based VLPs have been used in medical studies. However, to our knowledge, the potential application of plant/insect virus-based VLPs in agriculture remains largely underexplored. This review focuses on why and how to engineer coat proteins of plant/insect viruses as functionalized VLPs, and how to exploit VLPs in agricultural pest control. The first part of the review describes four different engineering strategies for loading cargo at the inner or the outer surface of VLPs depending on the type of cargo and purpose. Second, the literature on plant and insect viruses the coat proteins of which have been confirmed to self-assemble into VLPs is reviewed. These VLPs are good candidates for developing VLP-based agricultural pest control strategies. Lastly, the concepts of plant/insect virus-based VLPs for delivering insecticidal and antiviral components (e.g., double-stranded RNA, peptides, and chemicals) are discussed, which provides future prospects of VLP application in agricultural pest control. In addition, some concerns are raised about VLP production on a large scale and the short-term resistance of hosts to VLP uptake. Overall, this review is expected to stimulate interest and research exploring plant/insect virus-based VLP applications in agricultural pest management. © 2023 Society of Chemical Industry.

Side effects of two citrus essential oil formulations on a generalist insect predator, plant and soil enzymatic activities.

The widespread use of chemical pesticides for crop protection, despite having contributed to ensure food security, have shown to exert negative impacts on the environment and on human health. In addition, the frequent emergence of resistance to pesticides and their adverse effects toward non-target organisms have generated the need to develop novel ecofriendly tools for pest control. Among these, plant essential oils (EOs) may play a central role in arthropod pest control. Recently, two formulations (Emulsion and PEG-nanoparticles) of three citrus EOs (lemon, mandarin and sweet orange) showed a promising potential against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a key tomato pest. Here, we evaluated the side effects of these experimental insecticides active substances toward (i) the generalist predator of several tomato pests, Nesidiocoris tenuis Reuter (Hemiptera: Miridae); (ii) the soil enzymatic activities (dehydrogenase activity, alkaline phosphomonoesterase, acid phosphomonoesterase and urease) and (iii) the tomato plant antioxidant enzymes (ascorbate peroxidase, catalase, superoxide dismutase and polyphenol oxidase). Among the tested formulations, mandarin EO-based insecticide presented a significant impact on the predator survival and reproduction. Conversely, all the tested compounds proved to be harmless for the soil enzymatic and the plant antioxidant activities. Overall, these results provide solid bases for the development of novel biopesticides for sustainable tomato crop protection.