Project description:To determine Sigma 54 (SigL) reglons in Bacillus thuringiensis HD73 strain, A sigLmutant, HD(ΔsigL::kan), was constructed with insertion of kanamycin resistance gene cassete. We have employed whole genome microarray expression profiling as a discovery platform to identify the difference of gene expression between mutant and wild-type strains.
Project description: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.
Project description:Transcriptional profiling of C. elegans nasp-1 / btr-1 mutant worms versus wild type N2 strain, both exposed to the bacterial pathogen Bacillus thuringiensis DB27.
Project description:Bacillus thuringiensis, a well-known and effective bio-insecticide, has attracted considerable attention as a potential biological control agent for the suppression of plant diseases. Treatment of tomato roots with a filter-sterilized cell-free filtrate (CF) of B. thuringiensis systemically suppresses bacterial wilt caused by Ralstonia solanacearum through systemic activation of the plant defense system. Comparative analysis of the expression of the Pathogenesis-Related 1(P6) [PR-1(P6)] gene, a marker for induced resistance to pathogens, in various tissues of tomato plants treated with CF on their roots suggested that the B. thuringiensis-induced defense system was activated in the leaf, stem, and main root tissues, but not in the lateral root tissue. At the same time, the growth of R. solanacearum was significantly suppressed in the CF-treated main root tissue but not in the CF-treated lateral root tissue. This distinct activation of the defense reaction and suppression of R. solanacearum were reflected by the differences in the transcriptional profiles of the main and lateral tissues in response to the CF. In the CF-treated main root tissue, but not CF-treated lateral root tissue, the expression of several salicylic acid (SA)-responsive defense-related genes was specifically induced, whereas jasmonic acid (JA)-related gene expression was either down-regulated or not induced in response to the CF. On the other hand, genes encoding ethylene (ET)-related proteins were induced equally in both the main and lateral root tissues. Taken together, the co-activation of SA-dependent signaling pathway with ET-dependent signaling pathway and suppression of JA-dependent signaling pathway may play key roles in B. thuringiensis-induced resistance to R. solanacearum in tomato plants. Gene expression was measured in main and lateral root tissues of tomato treated with Bacillus thuringiensis or distilled water-treated control at 48 hours after treatment. Two independent experiments were performed at each tissue (main root or lateral root tissue) for each treatment (Bacillus thuringiensis or distilled water control).
Project description:This research aims at studying the responses of Bacillus thuringiensis NEB17 to salt (NaCl) stress, and the secreted proteins in the cell-free supernatant at 42h of bacterial growth, using LC-MS/MS.
Project description:Transcriptional profiling of C. elegans nasp-1 / btr-1 mutant worms versus wild type N2 strain, both exposed to the bacterial pathogen Bacillus thuringiensis DB27. One-condition experiment. C. elegans nasp-1 / btr-1 mutant versus N2, exposed to Bacillus thuringiensis DB27. 3 biological replicates, including 1 dye-swaps.