| Clubroot disease is an important disease of cruciferous crops caused by Plasmodiophorabrassicae Woron,leads to subsequent reductions in crop yield.Clubroot disease is difficult to control by either chemical or cultural practices.Many strategies have been proposed,however,the development of resistant cultivar is believed to be the most effective and environmentally friendly.The purpose of this experiment was to explore the resistance gene.The results were as following:1 The identification of resistance showed that B.rapa T1-145 was high susceptible after XC(Xichang)strains.T1-145 was resistance to DY isolates,and tolerant for SF(Shifang)and LJ(Luojiang)isolates.Notably,T1-145 formed small spherical gall after inoculated with SF and LJ isolates,which is a kind of disease-resistance way;There are certain differences about the size,growth position and quantity of SSG,and the spore maturity after SF and LJ infection.2 Aceto-orcein staining was used to determine the germination of dormant spores in these tumors.The results showed that the germination rate of spores formed by XC strains was the highest,followed by SF and DY.The infection process of T1-145 by XC,SF and DY strains showed that the root hair infection time was 4 dpi,but the number of root hairs infected by XC strains was the most,that of SF strains was second;The time of infection and the number of zoosporocyst in the cortex were different.The infection time of the XC,SF and DY strains was 9 dpi,10 dpi and 12 dpi,respectively.At the late infection period,the zoospore distribution of XC strains was dispersed,the distribution of SF and DY strains is concentrated.Finally,the T1-145 roots infected by XC strains formed typical spindle galls,SF strains formed small spheroid galls,and DY strains did not form symptom.We found the secondary zoospore could infected cortex and root hair simultaneously,and the infection time was 5 dpi.At 12 dpi,the number of zoosporangium in the root hairs and cortex increased.At 20 dpi,the zoosporangium were become disperse,and the number of zoosporangium in the T1-145 roots decreased significantly.3 Using high-throughput sequencing technology sequence 12 samples obtained at different stages of T1-145 by XC and SF infection,After sequence filtering and assembly,atotal of 800485764 clean reads were obtained,and the total number of clean bases was131.05 Gb.A total of 2232 differentially expressed genes were obtained.The expression level of these genes in the SF isolates-infected samples was higher than that of the XC strains-infected material.By comparing the expression patterns of these genes in the materials infected by SF and XC strains,some induced defense-related genes were screened.Including NB-LRR-like resistance proteins,such as RML1 B,CSA1,RPS6 and TAO1.Receptor genes,such as CDPK,WAK,LecRK,RLP12,and RPW8,which are also induced to express and may play an important role in activating the basic defense response.In addition,there are genes related to chitinase,pathogenicity-related proteins,defensin-related proteins,and tumor suppressor genes,which are also induced in the infection by P.brassicae brassicae and may promote the quantitative resistance of T1-145 with the P.brassicae brassicae.And select 9 potentially resistant genes.4 In this study,the recombinant vectors of 9 candidate gene were constructed,and the transform of Arabidopsis thaliana were performed by Agrobacterium tumefaciens AGL1.The transgenic seeds were obtained.Their functions still need to be further verified... |
PDF Full Text Request