Study On Expression Analysis Of Genes Related To White Rust Resistance Of Chrysanthemum

Chrysanthemum is one of the ten traditional flowers in China,but the chrysanthemum white rust is one of the main diseases of cultivated production hazards,and spread in Chrysanthemum,which has been included in the worldwide quarantine disease.A transcriptional group was sequenced in the previous research,and the differentially expressed genes,CmHSP,CmHSPL gene and Cm WRKY gene were obtained.In this study,real time fluorescence quantitative PCR technique was used to analyze the expression patterns of the three resistance related genes under different stresses in Chrysanthemum.The vector p BI121-CmWRKY was constructed and was transformed into Agrobacterium,which will be significance to breed resistant varieties Chrysanthemum.The main results are as follows:1.We analyze the gene expression patterns of chrysanthemum after abiotic stress?high salt,drought,high temperature,low temperature?by real-time quantitative PCR.The results show that the expression of CmHSP and CmHSPL genes and CmWRKY genes induced by high salt and high temperature stress.At high salt treatment for 0.5h,the expression levels of the three genes were 1.6,2.5 and 6.6 times that of the control group,respectively.At high temperature for 0.5h,the expression levels of the three genes were 368.7,15.1 and 13.2 times that of the control group,respectively.The expression of CmHSP and CmHSPL genes and CmWRKY genes were down-regulated when plants were exposed to low temperature stress.It indicated that low temperature stress inhibited the expression of three genes of chrysanthemum.Drought stress inhibited the expression of CmHSP and CmHSPL genes,but the CmWRKY gene was not induced by its expression.2.We analyze the gene expression patterns of chrysanthemum after phytohormone treatment like Ethrel?Eth?,Salicylic Acid?SA?,Methyl Jasmonate?MeJA?by real-time quantitative PCR.The results show that the response of CmHSP and CmHSPL genes induced by SA and MeJA was obvious,while the response induced by Eth was not obvious.The expression of CmWRKY gene was rapidly responded to by Eth,SA and MeJA.The expression of CmWRKY gene was highest at 1h after treatment.3.We analyze the gene expression patterns of chrysanthemum after bio-stress?chrysanthemum white rust pathogen?by real-time quantitative PCR.The results show that CmHSP,CmHSPL genes and CmWRKY gene are involved in the disease resistance response of Chrysanthemum white rust,response and expression highly and rapidly,in processing 6h to complete the high level expression.The expression level of CmHSP and CmHSPL gene reached the highest level at 4h and 6h after treatment respectively,21.1 times and 10.4 times of that of control group,while the expression level of CmWRKY gene reached the highest value at 1h after treatment,which was 426 times of that of control group.This is consistent with the results of transcriptome sequencing in the previous research,indicating that all three genes are involved in the disease resistance of Chrysanthemum white rust and participate in the plant defense response.4.The plant recombinant expression vector p BI121-CmWRKY was successfully constructed.The Agrobacterium was prepared into competent cells by CaCl₂,and the recombinant plasmid pBI121-Cm WRKY was transformed into Agrobacterium by freezing thawing method,which lay the foundation for further research of transgenic plants and further research on the function of transcription factor.