Navigational signals for insect and slug parasitic nematodes : the role of ascorbate–glutathione system and volatiles released by insect-damaged sweet pepper roots

Laznik, Žiga (author), Križman, Mitja (author), Zekič, Jure (author), Roškarič, Mihaela (author), Trdan, Stanislav (author), Urbanek Krajnc, Andreja (author)

This study of underground multitrophic communication, involving plant roots, insects, and parasitic nematodes, is an emerging field with significant implications for understanding plant–insect–nematode interactions. Our research investigated the impact of wireworm (Agriotes lineatus L. [Coleoptera: Elateridae]) infestations on the ascorbate–glutathione system in sweet pepper (Capsicum annuum L.) plants in order to study the potential role in root-exudate-mediated nematode chemotaxis. We observed that an A. lineatus infestation led to a decrease in leaf ascorbate levels and an increase in root ascorbate, with corresponding increases in the glutathione content in both roots and leaves. Additionally, a pigment analysis revealed increased carotenoid and chlorophyll levels and a shift towards a de-epoxidized state in the xanthophyll cycle. These changes suggest an individual and integrated regulatory function of photosynthetic pigments accompanied with redox modifications of the ascorbate–glutathione system that enhance plant defense. We also noted changes in the root volatile organic compound (VOC). Limonene, methyl salicylate, and benzyl salicylate decreased, whereas hexanal, neoisopulegol, nonanal, phenylethyl alcohol, m-di-tert-butylbenzene, and trans-β-ionone increased in the roots of attacked plants compared to the control group. Most notably, the VOC hexanal and amino acid exudate cysteine were tested for the chemotaxis assay. Nematode responses to chemoattractants were found to be species-specific, influenced by environmental conditions such as temperature. This study highlights the complexity of nematode chemotaxis and suggests that VOC-based biological control strategies must consider nematode foraging strategies and environmental factors. Future research should further explore these dynamics to optimize nematode management in agricultural systems.

• Language: English
• Keywords: Capsicum annuum, Agriotes lineatus, ascorbate–glutathione system, root volatile compounds, entomopathogenic nematodes, slug parasitic nematodes
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 14 str.
• Numbering: Vol. 15, no. 10, art. 805
• PID: 20.500.12556/RUL-164267
• UDC: 632
• ISSN on article: 2075-4450
• DOI: 10.3390/insects15100805
• COBISS.SI-ID: 212072195
• Publication date in RUL: 18.10.2024

Record is a part of a journal

• Title: Insects
• Shortened title: Insects
• Publisher: MDPI
• ISSN: 2075-4450
• COBISS.SI-ID: 519122457

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: entomopatogene ogorčice, obrambni mehanizem rastlin, varstvo rastlin