Insecticidal Activity and Mechanism of 7-Methylcoumarin Against Diaphorina citri Reveal the Role of Chemosensory Genes in Defense Response.
- 1National Navel Orange Engineering Research Center, College of Life Sciences, Gannan Normal University, Ganzhou 341000, China.
- 2Jiangxi Provincial Key Laboratory of Pest and Disease Control of Featured Horticultural Plants, Gannan Normal University, Ganzhou 341000, China.
Abstract
The Asian citrus psyllid (Diaphorina citri) is a major vector of Huanglongbing (HLB), a devastating citrus disease worldwide. In addition to vectoring HLB, D. citri is a significant economic pest in its own right, causing direct damage to citrus by feeding on tender shoots, leading to leaf distortion, shoot dieback, and sooty mold infestation. Chemical control remains the primary strategy for managing D. citri populations, but heavy reliance on insecticides has led to insecticide resistance. Coumarin and its derivatives, as a natural product, are widely recognized for their insecticidal activities against various agricultural pests. In this study, the insecticidal activity of 11 coumarin compounds against D. citri nymphs was evaluated by bioassay, among which 7-methylcoumarin exhibited the most substantial efficacy. Moreover, the insecticidal mechanism of 7-methylcoumarin was assessed by a comparative transcriptome analysis, and 294 differentially expressed genes (DEGs) were identified, including 165 up-regulated and 129 down-regulated genes. GO enrichment analysis showed that DEGs were mainly involved in extracellular region/space, (chitin-based) cuticle development, and structural constituent of (chitin-based) cuticle terms, especially down-regulated genes related to cuticle proteins, chemosensory proteins and odorant-binding proteins, which were further verified by qPCR. Among chemosensory genes, only DcCSP2 was significantly up-regulated, indicating its potential involvement in the defense response of D. citri. Suppression of DcCSP2 via RNAi significantly increased susceptibility to 7-methylcoumarin in D. citri nymphs. Molecular docking revealed that 7-methylcoumarin binds within the internal hydrophobic cavity of DcCSP2. This finding provided a potential molecular mechanism underlying the action of coumarin compounds against pest insects and may contribute to facilitating the development of new strategies for managing insecticide resistance.
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BibTeX
@article{fang2026insecticidal,
title = {{Insecticidal Activity and Mechanism of 7-Methylcoumarin Against Diaphorina citri Reveal the Role of Chemosensory Genes in Defense Response.}},
author = {Ao Fang and Xue-Yan Wang and Zheng-Hui Zou and Tong Yang and Wei Chen and Hai-Zhong Yu and Bing-Qi Liu and Ying-Xue Liu and Zhan-Jun Lu and Xiao-Qiang Liu},
journal = {Insects},
year = {2026},
month = oct,
doi = {10.3390/insects17101045},
url = {https://europepmc.org/article/MED/42940954},
note = {CC BY},
}
RIS
TY - JOUR
TI - Insecticidal Activity and Mechanism of 7-Methylcoumarin Against Diaphorina citri Reveal the Role of Chemosensory Genes in Defense Response.
AU - Ao Fang
AU - Xue-Yan Wang
AU - Zheng-Hui Zou
AU - Tong Yang
AU - Wei Chen
AU - Hai-Zhong Yu
AU - Bing-Qi Liu
AU - Ying-Xue Liu
AU - Zhan-Jun Lu
AU - Xiao-Qiang Liu
PY - 2026
DA - 2026/10/12
JO - Insects
DO - 10.3390/insects17101045
UR - https://europepmc.org/article/MED/42940954
AB - The Asian citrus psyllid (Diaphorina citri) is a major vector of Huanglongbing (HLB), a devastating citrus disease worldwide. In addition to vectoring HLB, D. citri is a significant economic pest in its own right, causing direct damage to citrus by feeding on tender shoots, leading to leaf distortion, shoot dieback, and sooty mold infestation. Chemical control remains the primary strategy for managing D. citri populations, but heavy reliance on insecticides has led to insecticide resistance. Coumarin and its derivatives, as a natural product, are widely recognized for their insecticidal activities against various agricultural pests. In this study, the insecticidal activity of 11 coumarin compounds against D. citri nymphs was evaluated by bioassay, among which 7-methylcoumarin exhibited the most substantial efficacy. Moreover, the insecticidal mechanism of 7-methylcoumarin was assessed by a comparative transcriptome analysis, and 294 differentially expressed genes (DEGs) were identified, including 165 up-regulated and 129 down-regulated genes. GO enrichment analysis showed that DEGs were mainly involved in extracellular region/space, (chitin-based) cuticle development, and structural constituent of (chitin-based) cuticle terms, especially down-regulated genes related to cuticle proteins, chemosensory proteins and odorant-binding proteins, which were further verified by qPCR. Among chemosensory genes, only DcCSP2 was significantly up-regulated, indicating its potential involvement in the defense response of D. citri. Suppression of DcCSP2 via RNAi significantly increased susceptibility to 7-methylcoumarin in D. citri nymphs. Molecular docking revealed that 7-methylcoumarin binds within the internal hydrophobic cavity of DcCSP2. This finding provided a potential molecular mechanism underlying the action of coumarin compounds against pest insects and may contribute to facilitating the development of new strategies for managing insecticide resistance.
SN - 2075-4450
ER -