Effects Of The Oviposition Of Saperda Populnea On The Gene Expression Of The Branch Bark Of Populus × Xiaohei

Populus×xiaoheiT.S.Hwang et Liang is an important economic and greening tree species in China,which was hybridizated between Populus nigraand Populus simonii.It has the advantages of rapid growth,easy vegetative propagation,high drought resistance and cold resistance,and strong ability to resist diseases and insect pests,etc.Because of its fine materials,it is also used for papermaking,matchsticks,and construction,etc.And because it is suitable for growing in cold and arid regions in north of China,it has become a green tree species that has been promoted by the drought-prone areas in north of China.But the stem pests which name is Saperda populnea L.is affecting the growth of black poplar seriously.This pest is mainly harmful to the branches of tree.Its larvae diverted between the xylem and phloem in the trees after insect ovulation,and it will grow to a small insects,which is hindered the normal transportation of nutrients and moisture of poplars seriously,and become a tumor in the branches of the tree,it will cause branches of thee become dry and even windy when severe,and the tree crown become bald deformity,which would affect the growth of Black Poplar.In this reach,using the branches of black poplar which were spawning by the S.populnea L.in those for experimental materials and pinned hole drilling as comparison.Sequencing the two different processing conditions of branches of black poplar by using transcriptome sequencing through the sequencing platform of Illumina,obtained related genes that play a key role in the formation of S.japonicum through the bioinformatics analysis of the obtained transcriptome data.Analysis the expression of the related genes of been insects in black poplar through the Quantitative Real-time PCR and the significant genetic differences through SPSS base on the data of transcriptome sequencing.To provide a theoretical basis for the further study of the mechanism for the formation of galls on the branches of Populus simonii after spawning,and also provide the basis for the further search for effective methods to prevent.The main results were as follows:1.The morphology of Populus×xiaohei worms after spawning.After the male and female adults of Poplar beetle meet,the female adult will carve"horseshoe" mark on the branch of poplar,and arrange the dotted line in the shape of "U".The female adult produces the egg at the junction of the xylem and phloem.Poplar beetles secrete chemicals on their spawning surfaces,and the bark of poplar responds to stimuli.The changes of poplar branches were observed in 4～6 hours(1 hour,4～6 hours,12 hours,24 hours,48 hours,3 days and 5 days after oviposition).2.Determination of enzyme activity after spawning of aspen beetle the polyphenol oxidase.Catalase,superoxide dismutase,malondialdehyde,soluble sugar in poplar phloem from spawning stage to gall production stage were measured.Proline content coordinated to prevent free radical invasion.3.Analysis of transcriptome sequencing for the Populus×xiaohei worms after spawning.Contig,unigene and transcript were obtained after the total RNA was extracted,cDNA library was prepared,and transcriptome sequencing was performed on Populus×xiaoheiworms after spawning,which were found to be associated with Populus×xiaohei.And 2124 genes were found which were related to the formation process of Populus×xiaohei worms after spawning,and Unigene was compared with the NR,Swiss-Prot,KEGG,COG,and GO databases annotated 1354 Unigenes,Nr,Swiss-Prot,COG,and KEGG databases are annotated separately.The Unigene can be divided into three major species by the GO database.The unigene sequences of the biological process are total,the unigene sequence of the cells is a total of unigene sequences,and the unigene sequence is a total of the molecular functions;the unigene gene is divided into classes by the COG database.Unigene is the most common;the unigene sequence annotated with the KEGG database alignment is divided into the metabolic pathways,of which the unigene pathway is the most.Through differential expression analysis,differentially expressed genes were obtained and a total of GO functional categories and metabolic pathways were obtained.Compared with the control group,it was found that one of the Unigenes was down-regulated at 24 h after spawning by Populus×xiaohei worms,accounting for 2 124 Unigenes;the other genes were up-regulated.4.The expression analysis of the process for Populu×xxiaohei worms after spawning.Based on the transcriptome sequencing data of Populus×xiaohei worms after spawning,the expression of hyb2 which is a gene related to of Populus×xiaohei worms after spawning,was analyzed by real-time quantitative PCR.The results showed that the highest expression of hyb2 gene was observed at 24 hours after spawning and mechanical injury of Populus xxiaohei,followed by at 3 days after spawning and mechanical injury of Populus xxiaohei,the expression at 2 days after spawning and mechanical injury of Populus×xiaohei was the lowest.Then the SPSS software was used to analyze the difference in the expression of the hyb2 gene.Under the level of P<0.05,the expression of the hyb2 gene was not significantly different between spawning and mechanical injury at 24h,2d,and 4d.This also indicates that the gene may be related to the formation of moth larvae of Populus×xiaohei,which is caused by spawning and mechanical damage of Populus×xiaohei at 24 h.