Aug 2026· Journal of Agricultural and Food Chemistry· 0 citations· 52 references
TL;DR
It is suggested that DMNT plays an important role in mediating tritrophic interactions among cowpea, leafminers, and parasitoid wasps, and the mechanism underlying its herbivory-induced emission is elucidated.
Abstract
Understanding the roles of herbivore-induced plant volatiles (HIPVs) in regulating plant–herbivore–natural enemy interactions is essential for developing integrated pest management strategies. In this study, we found cowpea infested by leafminers (Liriomyza sativae) repelled the herbivores and attracted their natural enemy Neochrysocharis formosa, accompanied by the emission of large amounts of (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT). Bioassays confirmed that DMNT simultaneously repelled L. sativae and attracted N. formosa. In addition, DMNT triggered jasmonic acid (JA) and salicylic acid (SA) biosynthesis in neighboring plants, activating plant-to-plant defense signaling. Further assays demonstrated that the enhanced expression of the nerolidol synthase gene VuNES, mediated by JA signaling, was the key factor promoting DMNT emission. These findings suggest that DMNT plays an important role in mediating tritrophic interactions among cowpea, leafminers, and parasitoid wasps, and elucidate the mechanism underlying its herbivory-induced emission. Our study provides a theoretical foundation for developing sustainable, DMNT-based strategies for integrated pest management.
The results support the use of T. harzianum as an effective bioinoculant to enhance plant growth and suppress pests, offering a sustainable alternative to synthetic agrochemicals.
Blanca A. ESQUIVEL-AYALA, Margarita Vargas-SandÓVal, M. P. Chaires-Grijalva et al.· Pest Management Science· 0 citations
Populus hopeiensis is an important native poplar species in northern China, but herbivorous insect damage seriously affects its growth and ecological function. WRKY transcription factors play important roles in plant stress responses; however, the function of WRKY23 homologs in woody plant resistance to chewing herbivores remains unclear. In this study, a herbivore-responsive WRKY transcription factor gene, PhWRKY23, was identified from P. hopeiensis. PhWRKY23 expression was significantly induced by Spodoptera litura feeding, with a maximum increase of approximately 69.71-fold the control level at the highest damage level, and the encoded protein was predominantly localized in the nucleus. To investigate its function, PhWRKY23-overexpressing and RNA interference transgenic lines were generated. In the choice feeding assay, the consumed leaf area of PhWRKY23-overexpressing plants was approximately 85.5% lower than that of WT plants after 8 h. In the no-choice feeding assay, the total larval mass after 6 d was approximately 38.8% lower in larvae fed on overexpression plants and 51.0% higher in larvae fed on RNAi plants than in those fed on WT plants. Physiological analysis showed that RNAi plants accumulated significantly more MDA than WT and overexpression plants, whereas overexpression plants had higher chlorophyll a, chlorophyll b, and carotenoid contents than the other genotypes. Phytohormone analysis further showed that PhWRKY23-overexpressing plants accumulated higher levels of jasmonic acid, jasmonoyl-L-isoleucine, and salicylic acid, whereas abscisic acid showed no significant difference among genotypes. Yeast two-hybrid screening identified several candidate PhWRKY23-interacting proteins, and pairwise validation confirmed that PhWRKY23 interacted with PhDOX1 in yeast. These results indicate that PhWRKY23 positively contributes to herbivore resistance in P. hopeiensis and that this resistance phenotype is associated with changes in JA, JA-Ile, and SA accumulation and defense-related physiological traits.
Qi Zhang, Jia-Xin Liu, Yu’e Bai et al.· Plants· 0 citations
Tomato (Solanum lycopersicum) is an important agricultural crop frequently threatened by pests such as Bradysia impatiens (B. impatiens), a globally distributed sciarid fly whose larvae inflict severe damage on roots, stems, and leaves, leading to substantial yield losses. Despite its economic importance, the molecular and metabolic mechanisms underlying tomato defense against B. impatiens remain poorly understood. In this study, integrated transcriptomic and metabolomic approaches were employed to investigate the responses of tomato leaves to B. impatiens larval infestation at one week post-infestation. In our experimental system, larvae were introduced onto the soil surface and sequentially fed on stem bases (causing seedling lodging), leaves of prostrate plants, and roots. The leaf responses therefore reflect a combination of direct larval feeding on leaf tissues and systemic effects resulting from stem and root damage. Herbivory induced extensive transcriptional reprogramming, with 2,973 differentially expressed genes (DEGs) significantly enriched in pathways related to MAPK signaling, plant hormone transduction, plant-pathogen interactions, and phenylpropanoid biosynthesis. Metabolomic analysis identified 1,462 differentially accumulated metabolites, indicating significant shifts in energy metabolism, antioxidant defense systems, and the biosynthesis of defense-related compounds such as terpenoids and phenylpropanoids. Combined analyses revealed synchronized induction of α-linolenic acid metabolism and jasmonate signaling, accompanied by increased accumulation of reactive oxygen species (ROS) and upregulation of ethylene-responsive factors (ERF), bHLH, and NAC transcription factors. These findings reveal a tiered defensive regulatory network in tomato that integrates signal perception, hormonal regulation, metabolic reconfiguration, and ROS-mediated responses to counteract B. impatiens infestation. This entire defensive cascade embodies herbivory-triggered induced resistance, accompanied by sustained adaptive metabolic remodeling to withstand continuous larval feeding pressure. This study provides a comprehensive perspective on tomato plant-insect interactions and identifies potential targets for enhancing tomato resistance through molecular breeding or ecological management strategies. Notably, the hub transcription factor gene MYC, JA rate-limiting biosynthetic gene 12-oxophytodienoate reductase 3 (OPR3), α-linolenic acid-derived oxylipins and phenylpropanoid metabolites are highlighted as promising molecular biomarkers and core targets for future tomato anti-fungus gnat resistance engineering.
Yumei Shi, Yongxiu Wang, Liangju He et al.· BMC Plant Biology· 0 citations
Western Flower Thrips (WFT) (Frankliniella occidentalis) is a major pest threatening ornamental floriculture, including Alstroemeria production. Conventional insecticide-based management is increasingly limited due to the development of resistance and concerns over non-target impacts. Plant defense elicitors such as methyl jasmonate (MeJA) and α-ionone (α-I) represent promising alternatives for priming endogenous metabolic pathways that deter herbivory. However, their roles in metabolite-related Alstroemeria defense activation and associated effects on detoxification-related enzyme activity in thrips remain insufficiently characterized. Thus, exogenous application of defense elicitors in Alstroemeria resulted in consistent reductions in thrips florivory across concentrations and time points, with MeJA at 300 ppm and α-I at 150 ppm showing the strongest and most reproducible antifeedant effects. Thrips feeding on elicitor‑treated tissues exhibited clear, treatment‑dependent variation of detoxification enzyme activity, including glutathione S‑transferases, esterases, and cytochrome P450 monooxygenases. In parallel, untargeted metabolomic analyses clearly distinguished elicitor‑treated plants from controls and revealed pronounced time‑ and tissue‑specific metabolic reprogramming, particularly reflected in the accumulation of phenylpropanoid‑ and flavonoid‑related features. Collectively, these results demonstrate that MeJA and α-I effectively enhance defense responses in Alstroemeria, plausibly constraining WFT feeding. The concordant patterns observed in florivory, insect enzyme activity, and plant metabolite-based responses support the view that elicitor‑driven induction of plant‑derived metabolites contributes to antifeedant effects while simultaneously reshaping dynamics of WFT detoxification enzyme activity. These findings highlight MeJA and α-I as viable elicitors that merit further investigation as components of sustainable thrips management.
Andrés F. Velasco-Cárdenas, Daniel Rodríguez, E. Coy-Barrera· PLoS ONE· 0 citations
