Introduction: The tea green leafhopper, Empoasca (Matsumurasca) onukii Matsuda, R., 1952 (Hemiptera: Cicadellidae), is currently one of the most devastating pests in the Chinese tea industry. The long-term use of chemical pesticides has a negative impact on human health, impeding the healthy and sustainable development of the tea industry in this region. Therefore, there is a need for non-chemical insecticides to control E. onukii in tea plants. The essential oils from plants have been identified for their potential insecticidal ability; however, there is a lack of knowledge regarding the effect of plant essential oils on E. onukii and its gene expression.
Methods: In order to address these knowledge gaps, the components of Pogostemon cablin and Cinnamomum camphora essential oils were analyzed in the present study using gas chromatography-mass spectrometry. The fumigation toxicity of two essential oils on E. onukii was tested using sealed conical flasks. In addition, We performed comparative transcriptome analyses of E. onukii treated with or without P. cablin essential oil.
Results: The 36-h lethal concentration (LC50) values for E. onukii treated with P. cablin and C. camphora essential oils were 0.474 and 1.204 μL mL−1 respectively. Both essential oils exhibited the potential to control E. onukii, but the fumigation activity of P. cablin essential oil was more effective. A total of 2,309 differentially expressed genes were obtained by transcriptome sequencing of E. onukii treated with P. cablin essential oil.
Conclusion: Many of differentially expressed genes were found to contain detoxifification genes, indicating that these families may have played an important role when E. onukii was exposed to essential oil stress. We also found differential expression of genes related to redox-related gene families, suggesting the upregulation of genes associated with possible development of drug and stress resistance. This work offers new insights for the prevention and management of E. onukii in the future.
Introduction: Gene expression analysis by reverse transcription quantitative polymerase chain reaction (qRT-PCR) has been widely used in research including insects. The selection of appropriate reference genes is the key to obtaining accurate and reliable results from qRT-PCR. However, studies on the expression stability of reference genes in Megalurothrips usitatus remain lacking.
Methods: In this study, qRT-PCR was used to analyze the expression stability of candidate reference genes in M. usitatus. The expression levels of six candidate reference gene transcription of M. usitatus were analyzed. GeNorm, NormFinder, BestKeeper, and ΔCt were used to analyze the expression stability of M. usitatus treated with biological factors (developmental period treatment) and abiotic factors (light, temperature, insecticide treatment, respectively). Comprehensive stability ranking of candidate reference genes was recommended by RefFinder.
Results and Discussion: Results showed that ribosomal protein S (RPS) was the most suitable expression in insecticide treatment. Ribosomal protein L (RPL) was the most suitable expression at developmental stage and light treatment, whereas elongation factor was the most suitable expression in temperature treatment. RefFinder was used to comprehensively analyze the above four treatments, and the results showed that RPL and actin (ACT) showed high stability in each treatment. Therefore, this study identified these two genes as reference genes in the qRT-PCR analysis of different treatment conditions of M. usitatus. Ourfindings will be beneficial for improving the accuracy of qRT-PCR analysis for future functional analysis of the target gene expression in M. usitatus.