Hormesis-Inducing Essential Oil Nanodelivery System Protects Plants against Broad Host-Range Necrotrophs

Abstract

Botrytis cinerea, a broad host-range necrotrophic (BHN) phytopathogen, establishes compatible interactions with hosts by deploying multigene infection strategies, rendering simply inherited resistance ineffective to fight off this pathogen. Since essential oils (EOs) serve as intermediators during phytobiome communication, we hypothesize that they have the potential to enhance the quantitative disease resistance against BHN by eliciting the adaptive stress response (hormesis) in plants. However, using EOs is challenging due to their poor solubility in water. Nanoemulsification of EOs enhances not only the solubility of EOs but also their potency and stability. Here, we demonstrate the potential use of essential oil nanoemulsions (EONEs) to control infections caused by BHN. Using basic engineering principles of nanocarrier design, we demonstrate the efficacy of a robust EONEs design for controlling B. cinerea infection in a model plant, Arabidopsis thaliana. Our nanoemulsion delivery system significantly enhanced the disease resistance of the host by reducing the necrotic area by up to 50% compared to untreated plants. RNA-seq analysis indicated that successful treatments upregulated autophagy, ROS scavenging, and activation of the jasmonic acid signaling pathway.

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

“…The formulation containing 95:5% d -limonene/SBO used in this work yielded a η D /η C in the optimal range (Supporting Information, Figure S3). These results are consistent with our previous results …”

“…These results are consistent with our previous results. 22 An optimized micelle-free finely tuned formulation may be possible using the net average curvature theory first described by Sabatini et al, 31 and further developed upon by Acosta et al, 32−34 but this objective is not within the scope of this work.…”

“…dlNE was obtained under lowenergy conditions at room temperature via spontaneous emulsification. The formulation method employed here followed the rational approach described by Vega-Vaśquez et al 22 Briefly, 5% w/w Dlimonene was added dropwise under constant magnetic stirring at room temperature into an aqueous solution containing propane- surfactant at a weight ratio of 3:1 with respect to the organic phase. Droplet formation and stability were assessed via TEM image analysis and DLS particle size distribution analysis.…”

“…Image-Based Phenotyping Studies. 4-week-old A. thaliana (Col-0) plants, independently grown under hydroponic conditions in 50 mL modified tubes with BNS as previously described, 24 were treated by exposing their roots to four different types of freshly prepared treatments according to Vega-Vaśquez et al 22 CSNPS, dlNE, and CdlNPs were the treatments under study. Each treatment was tested at four different concentrations (0.01, 0.1, 0.5, and 1% v/v) by diluting an aliquot of the previously prepared treatment solutions into BNS (50 mL final volume).…”

“…24 In brief, for the B. cinerea disease assay, four leaves from pretreated 4-week-old plants, grown under hydroponic conditions as previously described, were inoculated with 5 μL of a conidial suspension (2.5 × 10 5 spores/mL) of B. cinerea strain B05.10 in 1% w/v Sabouraud Maltose Broth and maintained under a transparent cover at a high humidity of 72 h. The necrotic area per leaf was measured via image-based phenotyping analysis using an ARIS B.V. automatic top-view imaging machine equipped with a multispectral light source (Aris, Eindhoven, The Netherlands) as described in the literature. 22 The chlorophyll-based masking segmentation was used to distinguish necrotic tissues in leaves. The necrotic area from individual leaves was measured using ImageJ software.…”