Transcriptomics Of Beauveria Bassiana And Its Infection On Anoplophora Chinensis

At present,insect pathogenic fungi have been widely used in pest biological control in agriculture and forestry systems.Among of them,Beauveria bassiana plays an important role in biological control of many pests.Anoplophora chinensis belonging to Cerambycidae of Coleoptera,is a wide range of harmful borers by eating trees,resulting in trees incapable of transmitting nutrients and even weak to death,which cause serious economic losses for forestry and urban greening.In current research,we explore that the differences at developmental stages of A.chinensis,infection interaction between B.bassiana and A.chinensis,B.bassiana differentially expressed genes(DEGs)in different media,and B.bassiana defense mechanisms with high temperature and UV stresses,respectively,investigate insect-pathogen interactions from multiple perspectives using transcriptome sequencing methods.The main results are showed as follows.1.Transcriptome analysis of A.chinensis at different developmental stagesTranscriptome analysis was employed in six samples of A.chinensis at different developmental stages(including egg,larva,elder larva,pupa,female adult and male adult),generating 2.3 Gb reads and assembling 78582 Unigene.Among the differences of gene expression analysis,the number of DEGs EGG vs LAs(larva)was 13791,including 3528 up-regulated and 10263 down-regulated genes.The GO and KEGG functional enrichment of DEGs showed that the major differences were enriched in the transcriptional regulation,energy supply,hydrolase activity,and highly conserved pathways involved in cell proliferation and differentiation,Notch and Wnt signaling pathways.Transcriptome data were screened for key proteins associated with development,olfaction and degradation of cellulose.Significant differences in insect hormone pathways and olfactory system-related proteins suggest that they may serve a critical role in the development,feeding and reproduction of A.chinensis.2.Expression differences of insect fungus B.in different mediaThe experiment of gene expression differences was conducted with conidia,conidia with germ tube and hyphae generated on different media including PDA(normal culture)and PDA combined with A.chinensis cuticle(induced culture)at the transcriptomics level,obtaining a total of 55.52 Mb reads,2.83 G base,and Q30 are more than 85%.When the expression level of the gene was calculated after alignment,the three samples found in the RPKM distribution of the six genes were generally higher than those of the normal culture.The enrichment of the GO function of differential genes indicated that the oxidation-reduction process and proteolysis were significantly enriched in multiple comparisons.A number of comparative KEGG metabolic pathway enrichment results were significantly enriched in amino sugar and nucleotide glucose metabolism,multiple amino acid metabolism,and transcriptional regulation.The gene expression pattern clustered found that the GO and KEGG of up-regulated expression pattern in the induced culture was enriched in the cytoskeleton formation,cycle and DNArelated metabolism.3.Preliminary study on transcriptome of A.chinensis infected by B.bassianaIn present research,the alignment rates of the five samples(CK,infection of A.chinensis at 12h,24h,36h and 48h by B.bassiana)were almost more than 60%,and the DEGs was differentially screened.In Bb12 vs Bb24,the most up-regulated genes were shown in the test.Functional enrichment of DEGs showed a significant enrichment involved the activity of the hydrolytic enzyme,the activity of the oxidoreductase,and the immune-related,detoxification and neurotransmission.In this experiment,the related factors of insect immune system were analyzed.Signal expression,serine-related phenolicoxidase cascade reaction and antimicrobial peptide and other related gene expression patterns were very similar,which were mainly activated for 12 h or 24 h,but were significantly increased at 48 h,suggesting that B.bassiana is still in germination or a little infection in the beginning of 12 h to 24 h attachment to A.chinensis,followed with stress and immune response.According to the transcriptome analysis of the immune related factors,it provided more ideas for future investigations on biological control of A.chinensis.4.Transcriptome of B.bassiana with temperature and UV stressesThe number of known genes was 92.01%for the three samples(untreated conidia,conidia treated with high temperatures of 32℃ and 37℃),and 521 new genes were also detected.As known that the growth of fungi under certain stress can increase the virulence of the strain and up-regulated gene was increased significantly in B32(conidia treated at 32℃).These related genes involved in invasion virulence.The predominant expression of profile 5 was the highest in B32,and protease,endoplasmic reticulum protein processing and endocytosis were significantly enriched in the pathways referring to misfolding of unfolded proteins or unfolded proteins.Significant upregulation of the proteasome pathway must be degraded by heat shock protein recognition.The expression levels of four Hsps were found to proliferate in B32 and also persistently expressed in B37(conidia treated at 37℃).Differences in gene screening also found that the expression of the trehalose-6-phosphate synthase of the antagonist protective agent trehalose synthase was significantly expressed in B32.The number of DEGs in BCK(untreated conidia)vs B80s(conidia treated with 80s radiation of UV)was 1787,including 1554 down-regulated genes.GO analysis showed that the relevant enzyme activity(included peptidase activity,catalytic activity,endopeptidase activity and oxidoreductase activity)GO terms were significantly enriched in the molecular functions.The enrichment of KEGG pathway mainly focused on protein processing and glucose metabolism,but the differential genes in most pathways are mainly down-regulated.In current study,single nucleotide mutations between samples were analyzed for sequencing data.Sequencing revealed 153573 mutation sites,of which SNP loci were 148301.Mutation sites are mostly located in the exon region,and the variation function statistics found that most of the synonymous mutation.