Analysis on Differentially Expressed Proteins in Tobacco Cultivar Dayemihe after Inoculation with Ralstonia solanacearum

Objective Dayemihe, a local famous and excellent tobacco variety in Fengkai County of Guangdong Province, is an excellent source of resistance to bacterial wilt currently. In-depth study of the mechanism of tobacco bacterial wilt resistance and search for differentially expressed proteins related to bacterial wilt resistance can provide a reference for the in-depth study of the molecular mechanism of anti-bacterial wilt and disease resistance breeding.

Method With tobacco variety Dayemihe, resistant variety D101 and susceptible variety as materials, inoculation and identification of bacterial wilt were conducted indoor. Differentially expressed genes of Dayemihe before and after inoculation were analyzed by Isobaric Tags for Relative and Absolute Quantitation(iTRAQ)and Quantitative Real-time PCR(qRT-PCR).

Result After inoculation, the development of the bacteria wilt of Dayemihe was slower than that of the susceptible control. Thirty-five proteins were differently expressed in Dayemihe: twenty-one proteins were down-regulated and fourteen proteins were up-regulated. Among them, twenty-five proteins were related to plant stress. The protein with the up-regulated differential expression with largest fold change was Hav1 belonging to the Nicotiana tabacum Agglutinin(Nictaba)family. The nictaba within 12 hours after inoculation was detected by qRT-PCR. It was found that they had the highest expression level at 6 hours and 9 hours after inoculation, and then the level began to decrease.

Conclusion Plant response to pathogen invasion is a complex process that requires proteins with different functions from different pathways. Plant response to pathogen invasion is a complex process. According to the identification, the protein with the up-regulated differential expression with largest fold change is Hav1, which belongs to the Nicotiana tabacum Agglutinin(Nictaba)family. Tobacco lectins showed similar expression patterns after inoculation with highly pathogenic and non-pathogenic strains, indicating that the lectin protein may play a role in the upstream reaction process after the invasion of pathogens.