Analysis Of Biochemical Indexs And Transcriptome Of Resistant And Susceptible In Plasmodiophora Brassicae Infected Canola(Brassica Napus )

Clubroot,infected by Plasmodiophora brassicae,is one of the most important diseases of brassicas in the world.The widespread of clubroot can caused serious declines in the quality and yield of oilseeds and vegetable of cruciferous crops.Plasmodiophora brassicae is a soil-borne obligate parasite,so measurement of it was very difficulted.Now,breeding resistant cultivars was one of the more effective way to control root diseases.Exploring the mechanism of plant resistanted disease has become the basis for selection of resistance varieties.In this study,on the basis of previous studies and in two kinds of Canola as the experimental material,biochemical mechanism and Molecular mechanism were studied.The research contents including pots experiment,the observation of root-hair infection rates and cortex colonization amounts.Exploring and analyzing thedefense enzymes(CAT/SOD/PPO/POD)activities,invertase activities,the contents of MDA,soluble protein and the soluble sugar the differences of defense enzyme related genes,hormone signal transduction related genes and defense response related genes were observed in Resistance and susceptible Canola by the infection of P.brassicae.1 The measurement of resistance or susceptibleThe results were as follows:Zhongshuang11hao(74.4%,46.0)was susceptible,6M80(37.8%,10.2)were resistant.With the method of solution culture,root-hair infection rates and cortex colonization amounts were investigate.The peak of root-hair infection rates and cortex colonization amounts of ZS11 significantly higher than 6M80.The peak of root-hair infection rates of ZS11 is 63.0%by 9dpi.The peak of root-hair infection rates of 6M80 is42.0%by 11dpi.It is showed that the main infection period ofP.brassicae is 3-15d.2 Difference analysis of biochemical index inclubroot of CanolaIn two kinds of Canola as the test material,testing theactivities change of CAT,SOD,PPO,POD,MDA,invertase,the content changes of soluble proteinand soluble sugar using the method of solution culture,at after and before inoculation.The study suggested that the activities of CAT was significantly higher than that of ZS11at the late stage of infestation,and the activities of SOD and POD of 6M80 were significantly higher than that of ZS11at before and after inoculation,so CAT related toclubroot-resistance of Canola,and SOD and POD was positively correlated with clubroot-resistance of Canola.PPO activity was no significant difference between6M80 and ZS11,so PPO was not related to clubroot-resistance to Canola.After inoculation withPlasmodiophora brassicae,the invertase activity of 6M80roots was significantly higher thanZS11,and there was a significant difference between6M80 and ZS11,soinvertase activitywas related to clubroot-resistance to Canola.After inoculation,the content of MDA in roots of ZS11 was significantly higher than6M80,while the content of soluble sugar in root of 6M80 was significantly higher than ZS11,that is,the content of MDA and soluble sugar in resistant material and susceptible materialwas significant difference,however,the content of soluble protein was no significant difference between 6M80 and ZS11.The suggested that MDAand soluble sugar wererelated to clubroot-resistance to Canola but soluble protein was not related to clubroot-resistance to Canola.3 Analysis of difference expression genes ofClubroot resistance and Susceptible canola infectedPlasmodiophora brassicaeA global transcriptome profiling of the roots of clubroot-resistant(6M80)and clubroot-susceptible(ZS11)of Canola was performed by RNA-seq,resceptively at 0,3,6,9,12 days post-inoculation(dpi),which totally geted 379,841,406 clean reads.The results showed that There were 6,607 different expression genes(DEGs)between control group(0dpi)and the treatments(3,6,9and 12dpi)in 6M80,while in ZS11,2,499 DEGs were found between control group and the treatments.Functional annotation showed that most of the differently expressed genes were involved in signal transduction,metabolism,transportation,and defense.Cultivars 6M80 and ZS11 had respectively82 and 53 DEGs of defense-related enzymes.The results showed that CATand SOD relatedgenes were involved in Hydrogen peroxidemetabolism and POD was involved in Ligninbiosynthesis.CAT related,SOD related and PODrelated genes expressed at each inoculation time is basically consistent with its activity.CAT related and SOD related genes were generally up-regulated in 6M80 and ZS11.POD related genes was generally up-regulated in6M80but the genes related to POD in were down-regulated at6 dpi.After inoculation,6M80 and ZS11 resceptively had 46 and 23 DEGs which were involved in plant-pathogen interaction.The results suggested that Ca~+influx codinggenes,espiratorybursgenest oxidase homologs(RBOH)genes,pathogenesis-related(PR)genes,heat shock protein(HSP90)geneswere up regulated,simultaneously,which promoted HR in 6M80,but in ZS11,Ca~+influx codinggenes and espiratorybursgenest oxidase homologs(RBOH)geneswere up regulated.After inoculation,32 and 15 DEGs were involved in SA,JA/ET signaling pathway,resceptivly in 6M80 and ZS11.In 6M80,SA signaling pathway was promoted and JA/ET signaling pathway was inhibited but the genes related ET biosynthesis were up-regulated,However,in ZS11,SA and ET signalingpathwayweretransiently activated,and eventually bothSA and JA/ET signaling pathways were inhibited.