Nanovaccine for Plants from Organic Waste: d-Limonene-Loaded Chitosan Nanocarriers Protect Plants against Botrytis cinerea

Abstract

Chitosan and D-limonene are bioactive molecules derived from organic waste. We repurposed them in the form of a drug delivery system for agricultural applications in crop protection to combatBotrytis cinerea, a broad host-range necrotrophic (BHN) pathogen that causes economic losses worldwide. Synthetic fungicide application remains the most common method to control this pathogen, but this comes with a significant environmental cost. Drug delivery systems from naturally occurring biomaterials can offer efficient treatment options to combat this pathogen. We hypothesized that engineered chitosan nanoparticles (CSNPs) loaded with D-limonene can trigger an ondemand systemic defense response in plants that enhances its quantitative disease resistance against BHN. Chitosan nanocarriers encapsulated with D-limonene as cargo were fabricated through a rational formulation via ionic gelation and the spontaneous emulsification method, respectively, to produce chitosan D-limonene nanoparticles (CdlNPs). The therapeutic effect of the Dlimonene nanoemulsion, CSNPs, and CdlNPs on the plants' defense response against necrotrophic fungal pathogens was evaluated by monitoring the dynamic morpho-physiological changes via multispectral image-based phenotyping in an Arabidopsis thaliana (Col-0)−B. cinerea model system. Functional analysis of the differentially expressed genes revealed that at the concentration of significant disease resistance (0.5%), CSNPs downregulated the biological process involved in plant growth and development, but upregulated the main process controlling response to stress.

Nanocarriers with Multiple Cargo Load—A Comprehensive Preparation Guideline Using Orthogonal Strategies

“…Similar to biomedical agents, nanocarriers formulated with plant bioactive such as pesticides or fungicides, allow on-demand plant protection. [162][163][164][165] Instead of sprayed onto the plants, loaded nanocarriers are injected into the trunk and can release the bioactive upon degradation. This approach requires no spraying and less bioactives, which has high potential for more sustainable and environmental-friendly plant protection.…”

Uncaria tomentosa-Loaded Chitosan Oligomers–Hydroxyapatite–Carbon Nitride Nanocarriers for Postharvest Fruit Protection

“…As in other drug delivery systems, the BNP release from the NCs is primarily expected to be dependent on the COS moiety and its pH-responsive behavior, which is associated with its amine and hydroxyl groups [48]. While a commercial chitosanase (EC 3.2.1.132) was chosen for assessing the release efficiency in this study, it is anticipated that the COSmediated release in the presence of the phytopathogen would occur due to the presence of organic acids in their secretomes, previously observed for other chitosan-based NCs used for controlling B. cinerea and S. sclerotiorum [49,50]. It is well-established that many postharvest fungi, such as B. cinerea, Colletotrichum spp., Monilinia spp., Penicillium spp., and S. sclerotiorum (which were tested herein), can secrete gluconic, oxalic, malic, fumaric, or citric acid [51][52][53].…”

Recent Development in Essential Oil-Based Nanocarriers for Eco-Friendly and Sustainable Agri-Food Applications: A Review

“…(A) Geraniol-loaded chitosan/gum arabic nanoparticles as effective insect repellants (reproduced with permission from ref ). (B) Chitosan nanocarrier encapsulated d -limonene as plant nanovaccine (reproduced with permission from ref ).…”

“…Apart from pesticide-based applications, EO-loaded chitosan nanocarriers are being evaluated against different plant diseases. Vega-Vaśquez et al 105 developed a nanovaccine for plants from a broad-host-range necrotrophic pathogen based on D-limonene-loaded chitosan nanocarrier (Figure 4B). NPs with an EE of 84% −92% were fabricated using the iongelation technique using sodium tripolyphosphate as a crosslinker.…”