Eliciting sweet pepper plant resistance to Aulacorthum solani and attractiveness on Aphelinus abdominalis by exposure to (Z)-3-hexenyl propanoate

Abstract

It is widely documented that plants respond to herbivory by releasing volatile compounds mediated by phytohormone signaling pathways. Herbivore-Induced Plant Volatiles (HIPVs), among which are the green leaf volatiles, can repel herbivores, attract their natural enemies, and warn neighboring plants of herbivore attacks. Plants that receive these warning signals activate defense mechanisms and therefore become more resistant to pests and diseases. In this work, we tested whether plants activated by exposure to the green leaf volatile (Z)-3-hexenyl propanoate [(Z)-3-HP)] can enhance the management of one of the most important pests of sweet peppers, the aphid Aulacorthum solani (Kalt.) (Homoptera: Aphididae). Here, we show that sweet pepper plants exposed to (Z)-3-HP induce plant defenses that repel A. solani winged adults and attract females of Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae), an aphid parasitoid used to control a plethora of aphid pests, including A. solani. Additionally, (Z)-3-HP-exposed plants were less infested by A. solani than their non-exposed counterparts under greenhouse conditions. Significant transcriptional differences were obtained when studying the temporal gene expression pattern of three defense-related genes, ASR1, PIN2, and AMP1, markers of abscisic acid, jasmonic acid, and salicylic acid, respectively, during the duration of the greenhouse experiment. Our results demonstrate how the use of volatiles as plant defense inducers can play a role in the management of A. solani in sweet pepper and opens the door to exploring this technique on other aphid pests in other crops.

Plant volatile-triggered defense in citrus against biotic stressors

“…(Peronosporales: Peronosporaceae) and Pseudomonas syringae Van Hall (Pseudomonadales: Pseudomonadaceae) in potato and tomato crops, respectively ( Payá et al., 2024 ). In commercial greenhouse contexts, the application of (Z)-3-hexenyl propanoate [(Z)-3-HP onwards] through slow-release dispensers was shown to reduce the susceptibility of plants to economically important pests such as Tuta absoluta (Meyrick) (Lepidoptera: Gelichiidae) in tomatoes ( Pérez-Hedo et al., 2021 ) and Aulocorthum solani (Kaltenbach) (Hemiptera: Aphididae) in sweet pepper ( Depalo et al., 2022 ). In tomatoes, the exposition of (Z)-3-HP induced the overexpression of genes associated with anti-herbivore defense, increasing the synthesis of compounds derived from fatty acids, activating the lipoxygenase pathway, and accumulating specific defense compounds ( Pérez-Hedo et al., 2021 ) All these findings converge on a deeper understanding of how Hervivore Induce Plant Volatiles (HIPVs) can be instrumentalized in integrated pest management strategies to activate plant defenses, enhance biological control, and ultimately reduce the dependence on synthetic pesticides in agriculture.…”

“…(Sapindales: Rutaceae), is utilized as a model system to examine the molecular responses triggered by exposure to the volatile (Z)-3-HP. This green leaf volatile (GLV) has been shown to activate plant defense mechanisms in other plant species ( Pérez-Hedo et al., 2021 ; Depalo et al., 2022 ; Riahi et al., 2022 ). By applying a novel approach that includes transcriptomic analysis using the genomes of both parentals, C. sinensis , and P. trifoliata , this work aims to decipher how exposure to (Z)-3-HP can modify plant-pest interactions.…”

Phenotypic plasticity plays an essential role in the confrontation between plants and herbivorous insects

“…Plant defenses against insect ingestion are varied and highly species-specific (Bustos-Segura et al 2022;Depalo et al 2022). Plant defenses can be divided into two categories: static, known as "constitutive defense, " and dynamic, known as "inducible defense. "…”