Document Type

Article

Publication Date

10-2025

Keywords

Type VI trichome, non-glandular trichome, Spodoptera exigua, adaxial surface, abaxial surface, feeding initiation

Abstract

Leaf trichomes in plants act as the first line of physical defence against herbivory, in addition to many other reported functions. Although trichomes have been found to vary intraspecifically and can be induced by herbivory, their interactive effects under additional factors, such as plant age and abaxial vs. adaxial leaf surfaces, are less understood. Here, using five common tomato varieties, we explored the effects of these factors and their interactions on trichome type and density. We quantified the densities of Type VI glandular trichomes, non-glandular trichomes, and total trichomes on abaxial and adaxial leaf surfaces, and total leaf trichomes with and without herbivory by Spodoptera exigua at both vegetative and reproductive stages. Further, we also tested whether the time taken to initiate feeding by S. exigua larvae could be influenced by the number of trichomes on the adaxial and abaxial surfaces. The results showed that there is significant variation intrichome densityamong varieties and leaf surfaces. Also, there were differences in herbivory-induced trichome production, with variable responses across varieties and growth stages. Bioassay results showed that insects took longer to initiate feeding on the abaxialleaf surfacethan on the adaxial surface, potentially due to the higher density of non-glandular trichomes on the abaxial side. Collectively, we report that the regulation and development of trichomes on theleaf surfaceof tomatoes is governed by multiple factors, with potential consequences for herbivore feeding, suggesting how physical defences play a significant role in insect-plant interactions.

Leaf trichomes are commonly considered as the first line of plant defense against insect herbivory. In this study, using 5 tomato varieties, we show that in addition to varietal differences, leaf side also influencestrichome density. And, larvae of Spodoptera exigua took significantly longer to feed on the leaf side that had highertrichome density, demonstrating the overall effects of tomato trichomes against herbivory.

Comments

Web of Science

Oxford

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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