Bacillus thuringiensis stains induced systemic resistance in Brassica napus L.

Bacillus thuringiensis has insecticidal activity against a variety of important agricultural pests and exhibits good bacteriostatic resistance to a variety of plant pathogens, and recentily study have shown that two strains of Bt (B88-82 and RG1-6 Strain) can induce the tomato to produce resistance to R. solanacearum. However, only the induced signal pathway has been studied, and its active substances are not reported. The aim of this study was to further explore the Bt strain that could induce plant disease resistance and study the induced activity of the Bt strain, and to study the signal pathway induced by transcriptional sequencing and fluorescence quantitative PCR. The results showed that there were 303 differentially expressed genes in rape after induction of 4F5 strain, among which 86 genes were up-regulated and 217 genes weredown-regulated. The result of 4BM1 strain induction was induced by transcriptase sequencing. There were 126 differentially expressed genes in rape. Among which 64 genes were up-regulated and 62 genes were down-regulated. The analysis of these differentialexpression genes revealed that they contained Salicylic acid pathway and Ethylene pathway-related genes, which need to be further verified. Overall design: Brassica napus L were treated with Bt strain 4F5, 4BM1, and stilled water as control. B. thuringiensis inoculum, the final density was 7.5×109 cfu, was sprayed on the root of 6-week-old rapeseed plants. The same volume of distilled water (DW) treatment as control. Five days after induction, rapeseed leaves were collected. For each treatment, 3 rapeseed seedlings were used.

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