Project description:We investigate the functional complexity of the Plutella xylostella transcriptome in defending against a Bt toxin using Illumina sequencing technology. Over 2,900 differentially expressed unigenes were obtained in resistant P. xylostella comparison to their susceptible counterpart.
Project description:We investigate the functional complexity of the Plutella xylostella transcriptome in defending against a Bt toxin using Illumina sequencing technology. Over 2,900 differentially expressed unigenes were obtained in resistant P. xylostella comparison to their susceptible counterpart. All the P. xylostella were maintained on cabbage.The susceptible strain (MM) was cultured without exposure to any Bt toxins.Before the sample collected, Cry1Ac-resistant P. xylostella were treated with 750μg/mL Bt toxin Cry1Ac to eliminate the heterozygous individuals. Then the survivors were collected after 48 hours and designed as the resistant sample (MK and GK). Then fourth-instars larvae midgut tissues of MK,GK and MM were collected, respectively, The RNA was extracted and sequenced using Illunima HiSeq 2000.
Project description:miRNAs play important roles in various biological processes through post-transcriptional regulation of gene expression. We previously identified 203 mature miRNAs in Diamondback moth, Plutella xylostella. This species has developed extremely high levels of resistance to chlorantraniliprole and other class of insecticides in the field. In this study, we examined the miRNA profile of P. xylostella in response to chlorantraniliprole exposure. The smRNA-seq data analyses showed that insecticide treatment caused significant changes in the abundance of some miRNAs. Increasing exposure time (6h to 24h) and insecticide concentration (0.01 to 0.1 ppm) induced more dysregulated miRNAs in DBM larvae.
Project description:A genomic insight into how an insect pest responds to the infection of a fungal insect pathogen, such as Beauveria bassiana, is critical for alternative strategy of insect pest contol based on fungal insecticides but has not been well probed. Here we constructed three pairs of digital expression libraries (transcriptomes) of Plutella xylostella (global lepidopteran pest) larvae 24, 36 and 48 hours post treatment of infection (hptI) and control (hptC) to reveal the host response to B. bassiana infection at genomic level. The paired libraries comprised 2144, 3200 and 2967 differentially expressed genes (DEGs) of P. xylostella at 24, 36 and 48 hptI/hptC, respectively. These DEGs were enriched in various immune pathways activated by the fungal infection, such as the pathways of complement and coagulation cascades, protein digestion and absorption, and drug metabolism - cytochrome P450. We found that 24 hptI was critical either for the cuticular penetration of B. bassiana or for the initial activation of the host defense system. The host immune response peaked at 36 hptI so that multiple defense mechanisms were activated against the fungal entry into the host hemocoel. At 48 hptI, many host genes involved in immunity and metabolism were downregulated, suggesting a success of fungal localization in the host hemocoel by overcoming the host defense reaction. Finally, we revealed that several fungal pathways could play important roles in the host-pathogen interaction, such as antioxidant activity, peroxidase activity and proteolysis. Up to 1636 fungal genes were co-expressed at the three time points, and 116 of them encode putative secretion proteins. Our results provide a novel insight into the pathogen-insect interaction and help to probe molecular mechanisms involved in the control of P. xylostella by B. bassiana. Here we constructed three pairs of digital expression libraries (transcriptomes) of Plutella xylostella (global lepidopteran pest) larvae 24, 36 and 48 hours post treatment of infection (hptI) and control (hptC) to reveal the host response to B. bassiana infection at genomic level