The Transcriptome Of Sitophilus Oryzae And The Regulation Of Stress To The Expression Of Associated Genes

The rice weevil Sitophilus oryzae, one kind of Coleoptera insect, is one of themost economically important pests, which causes serious damage to grainproduction. At present, S. oryzae was controlled mainly using phosphine. Fumigantphosphine show high insecticidal activity and osmosis. But the insect show highresistance to phosphine due to the long time usage of PH3recently. In recent years,more researches move there attention to find new technology to control of S. oryzae,e.g., biotechnology methods. Thus, elucidatting the molecular mechanism of theinsect resistant to phosphine is very important. In the present research, thetranscriptome of S. oryzae was sequenced using Solexa high-throughput sequencingtechnology. The sequences the genes associated with the resistances were analyzed.The effects of phosphine fumigate and high temperature on the expression of associatedgenes was analyzed. The above results supplied the genetic data about the S. oryzae,which provided the foundation for further sequencing of the complete genome,elucidating the molecular mechanisms of resistance and control by biotechnology.Using Solexa high-throughput sequencing technology, the transcriptomedatabase of Sitophilus oryza was obtained, which contained21,583,796reads,1,618,784,700nucleotude sequences,67,264Contigs and29,093unigenes. Byblastting in NCBI database,16,734unigenes can matche to the known proteins,which account for57.5%unigenes. The KEGG annotation result of Unigenesshowed that778Unigenes accounting for9.31%are related to ubiquitin system,512Unigenes (accounting for6.13%) are related to chromosome,489Unigenes(accounting for5.85%) are related to peptidases, only one Unigene is related tobiosynthesis of vancomycin group antibiotics, polyketide sugar unit biosynthesis,1,1,1-Trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) degradation and fluorenedegradation this four pathways.Seven gene familys related to the insecticide resistance were analyzed fromthe transcriptome database of Sitophilus oryza. There are16Unigenes encodingof Glutathione S-transferase (GSTs) family genes, including of the Delta, Sigma,Theta, Epsilon and Zeta classes. There are105Unigenes encoding of cytochromeP450; The numbers of Unigenes encoding of heat shock protein (HSP), juvenile hormone binding protein (JHBP), chitinase (CHI), odorant binding protein (OBP)and neuropeptide were33,18,23and34, respectively. Ten genes were indentifiedas encoding of insecticide targets, including of acetylcholinesterase (AchE) genes,c-aminobutyric acid receptor (GABA) associated protein genes, nicotinicacetylcholine receptor (nAChR)-alpha3,6,9,10subunit genes, oltage-gatedcalcium channel beta subunit genes and voltage-gated channel protein genes.The expression of associated genes of Sitophilus oryzae was quatified byReal-Time PCR. The stress of PH3can induce the increase of expression level ofGlutathione S-transferase family genes and the decrease of genes of insecticidetarget. The extent of the increase or decrease depended on the different genes.Under the stress of high temperature, the expression of heat shock proteinassociated genes will increase. The expression level of Hsp90, Hsp60and Hsp70genes increased significantly, but the Hsp40, Hsp10and Hsp21genes improvedslightly.