小菜蛾应对球孢白僵菌感染的免疫应答基因分析

Differential gene expression in diamondback moth Plutella xylostella in response to the infection of Beauveria bassiana

通过室内生物测定,筛选对小菜蛾Plutella xylostella具有高毒力的球孢白僵菌Beauveria bassiana菌株,分析小菜蛾应对球孢白僵菌浸染的免疫应答基因。采用新一代Illumina高通量测序技术对接种/感染48h与未接种的小菜蛾样品分别进行转录组测序,筛选差异表达基因;结合生物信息学分析差异表达基因的功能、分类及涉及的信号通路等。结果表明接种小菜蛾48h后诱导2 434个基因发生差异表达,包括1 080个上调基因和1 354个下调基因。GO分类结果表明,这些差异表达基因(DEGs)被注释到45个GO term中,包括23个生物学过程,12个细胞组分和10个分子功能。KEGG分析表明,1 308个DEGs被富集到25个功能途径,这些DEGs包括497个上调基因和811个下调基因。分析发现,DEGs编码蛋白包含肽聚糖识别蛋白、丝氨酸蛋白酶55、丝氨酸蛋白酶抑制剂以及细胞色素P450 6K1类的免疫相关蛋白。另外,组蛋白、磷酸泛酰半胱氨酸脱羧酶、双链RNA结合蛋白、黑芥子酶等基因在球孢白僵菌侵染过程中也高表达,推测这些基因可能参与小菜蛾应对球孢白僵菌侵染的免疫反应。研究结果为进一步研究小菜蛾免疫相关基因的功能奠定了基础。

The immune response genes in Plutella xylostella against a high virulent strain of Beauveria bassiana was investigated. Illumina high-throughput sequencing technology was employed to sequence the transcriptome of uninoculated and B. bassiana-inoculated P. xylostella. Differentially expressed genes（DEGs） and their functions, classification and signal pathways were analyzed in 48 h post inoculation using bioinformatic methods. Two thousand three hundred and thirty-four genes were significantly differentially expressed in the B. bassiana-inoculated insect as compared with the uninoculated control, including 1 080 up-regulated and 1 354 down-regulated genes. The DEGs were verified using q RT-PCR analysis. GO term enrichment analysis revealed that these DEGs could be assigned to 45 categories with 23 biological processes, 12 cellular components and 10 molecular functions. Four hundred and ninety-seven up-regulated genes and 811 down-regulated genes were enriched in 25 KEGG pathways. Some uncharacterized genes, such as histone, phosphopantothenoylcysteine decarboxylase, double stranded RNA binding protein, and myrosinase genes, were found to be dramatically upregulated during the infection process, suggesting that these genes might be related to the immune response in P. xylostella against the infection of B. bassiana.