Transcriptome analysis of Frankliniella occidentalis response to tomato defense mechanisms

To reveal the adaptation mechanism of Frankliniella occidentalis to tomato hosts and investigate its transcriptomic differences responding to plant defense, we used illumina sequencing to analyze the transcriptomes of F. occidentalis fed on tomato plants for 2 h (instantaneous response) and 24 h (long-term response); combined with GO and KEGG enrichment analyses, comparative transcriptomics identified key genes involved in the thrips' adaptation to host defense. The results revealed that compared with the control group, 72.79% and 71.92% of differentially expressed genes (DEGs) were up-regulated after 2 h and 24 h feeding treatments, respectively, with the number of up-regulated DEGs increasing over time. GO enrichment analysis indicated that under both instantaneous and long-term responses, genes associated with biological processes (including metabolic processes and sensory perception), as well as molecular functions (such as transporter activity, structural constituent of cuticle and molecular structural activity) potentially mediate the adaptation of F. occidentalis to tomato defense. KEGG enrichment analysis highlighted significant involvement of pathways associated with energy metabolism and allocation, signal transduction, and immune responses in mediating F. occidentalis adaptation to host defense regulation. Furthermore, we analyzed DEGs associated with digestive and detoxification enzymes across comparison groups. The results revealed that in the 2 h feeding group versus control, digestive enzymes (23 trypsins and 6 lipases), detoxification enzymes (14 cytochrome P450 and 12 carboxylesterase families) were detected; in the 24 h feeding group versus control, digestive enzymes (33 trypsins and 13 lipases), detoxification enzymes (28 cytochrome P450 and 16 carboxylesterase families) were observed; and in the 24 h versus 2 h comparison, digestive enzymes (12 trypsins and 3 lipases), detoxification enzymes (10 cytochrome P450 and 4 carboxylesterase families) were observed. Notably, the overall trend for these digestive and detoxification enzymes was up-regulated In summary, Genes associated with energy metabolism, signal transduction, and immunity exhibited heightened activity in F. occidentalis responding to tomato defense mechanisms, while DEGs encoding digestive and detoxification enzymes primarily mediated thrips adaptation to tomato plants through up-regulated expression.