Project description:Plant defense responses to biotic stresses are complex biological processes, all governed by sophisticated molecular regulations. Induced systemic resistance (ISR) is one of these defense mechanisms where beneficial bacteria or fungi prime plants to resist pathogen or pest attacks. In ISR the defense arsenal in plants remains dormant and it is only triggered by the infection, allowing a rapid response and a better allocation of plant resources. We recently described that the well-known beneficial bacterium Paraburkholderia phytofirmans PsJN is able to reduce Arabidopsis thaliana susceptibility to Pseudomonas syringae Pst DC3000 through ISR. Nevertheless, the molecular networks governing this beneficial interaction remain unknown. To tackle this issue we analyzed the temporal changes in the transcriptome of PsJN-inoculated plants before and after the infection with Pst DC3000 strain. These data were used to perform a gene network analysis to identify highly connected transcription factors that may be acting as hubs in controlling this ISR response. Before the pathogen challenge, strain PsJN regulated 405 genes (corresponding to 1.5% of the analyzed genome). PsJN-inoculated plants presented a faster and stronger transcriptional response 1-hour post infection (hpi) compared with the non-inoculated plants, which presented the highest transcriptional changes 24 hpi. A principal component analysis showed that PsJN-induced plant responses to the pathogen could be differentiated from those induced by the sole pathogen. Forty-eight transcription factors were regulated by PsJN 1 hpi, and a system biology analysis revealed a network with 4 modules where LHY, WRKY28, MYB31 and RRTF1 are highly connected transcription factors, that can be acting as hub regulators in this interaction. These modules are related to Jasmonate, Ethylene, Salicylic acid and ROS pathways. Additionally, the down- and up-regulation of ANAC32 and ORA59, respectively, support an important role of PDF1.2. These results indicate that a rapid and specific response of PsJN-inoculated plants to this virulent pathogen could be the pivotal element in the protection mechanism. A role for specific transcriptional regulators in the orchestration of this complex molecular response is also proposed
Project description:Plant growth promoting rhizobacteria (PGPR) induce positive effects in plants, such as increased growth or reduced stress susceptibility. The mechanisms behind PGPR/plant interaction are poorly understood, as most studies have described short- term responses on plants and only a few studies have analyzed plant molecular responses under PGPR colonization. Transcriptional profiles were determined by microarray analysis (Affymetrix ATH1 Genome Array) in Arabidopsis thaliana plants inoculated with the PGPR bacterial model Burkholderia phytofirmans PsJN
Project description:Whole transcriptome sequencing of B. phytofirmans PsJN colonizing potato (Solanum tuberosum L.) plants was used to analyze in planta gene activity and in the response of strain PsJN to plant stress in three different time points. The transcriptome of PsJN colonizing in vitro potato plants showed a broad array of functionalities encoded on the genome of strain PsJN. Our study indicates that endophytic B. phytofirmans PsJN cells are active inside plants. Moreover, the activity of strain PsJN is affected by plant drought stress, it senses plant stress signals and adjusts its gene expression accordingly.
Project description:This study investigated the transcriptomic response of Paraburkholderia busanensis P39 during exposure to fungal biomass of Colletotrichum scovillei KC05. RNA-seq was used to compare P39 grown alone with P39 exposed to fungal biomass, with three biological replicates per condition. The study aimed to identify transcriptional changes associated with fungal-biomass adaptation, nutrient scavenging, cell-envelope remodeling, regulatory responses, and interface-associated functions. Reads were aligned to the Paraburkholderia busanensis P39 genome represented by GenBank accessions CP058248 and CP058249.
Project description:Characterization of the transcriptomic responses of grafted tomato seedlings leaves after the root inoculations with the two beneficial microorganisms Paraburkholderia graminis and Azospirillum brasiliensis. Paraburkholderia graminis treatment led to a higher number of differentially expressed genes than Azospirillum brasiliensis, with a higher amount of up-regulated than down-regulated genes for both treatments. These DEGs were manly involved in response to oxidative stress, response to biotic and abiotic stress, water transport, regulation of transcription and hormones. Only few DEGs were shared among the two treatments, including genes involved in flowering time and in tolerance against abiotic stresses.