Project description:microRNAs can play a crucial role in stress response in plants, including biotic stress. Some miRNAs are known to respond to bacterial infection. This work has addressed the role of miRNAs in Manihot esculenta (cassava)-Xanthomonas axonopodis pv. manihotis (Xam) interaction. Illumina sequencing was used for analyzing small RNA libraries from cassava tissue infected and non-infected with Xam. Cassava variety MBRA685 (resistant to Xam-CIO151) Six-week-old plants were inoculated with 36h-old cultures of the aggressive Xanthomonas axonopodis pv. manihotis strain CIO151 in both leaves and stems.
Project description:Quorum sensing (QS) in Xanthomonas axonopodis pv. citri, the causal agent of citrus canker, is mediated by a diffusible signal factor (DSF). QS is required for the full virulence of X. axonopodis pv. citri in planta. Mutations in rpfF, rpfC and rpfG, the core genes of QS, decreased the production of extracellular proteases and bacterial motility. Comparison of the transcriptomes of QS mutants with that of the wild type stain revealed that QS temporally regulates the expression of a large set of genes, including genes involved in chemotaxis and flagellar biosynthesis, genes related to metabolism, genes encoding virulence traits such as type II secretion system substates, type III secretion system and effectors. Cross talk between the QS regulon and the HrpG regulon has also been identified by 62 common genes shared by both regulons. The temporal regulation of the QS regulon and cross talk with the HrpG regulon suggest the important role of QS in citrus canker infection, including attachment, invasion and growth in host apoplast.
Project description:Xanthomonas axonopodis pv. manihotis (Xam) is a gram negative bacterium causing Cassava Bacterial Blight (CBB), an important limitation for cassava production. The genetic bases underlying cassava resistance and susceptibility to different Xam strains are currently unknown. To identify genes and pathways important for the interaction, we used RNA-seq data to study transcriptomic changes in cassava plants inoculated with the non-pathogenic Xam strain, (ORST4) and a pathogenic strain, ORST4 transformed with the TAL effector TALE1Xam (ORST4+TALE1Xam). This analysis revealed that transcriptomic responses to both strains were very similar and were dominated by the induction of genes related to photosynthesis and phenylpropanoid biosynthesis and the down-regulation of genes related to jasmonic acid signaling, features possibly related to defense responses. Among the genes induced exclusively in cassava plants inoculated with ORST4 + TALE1Xam we found one gene containing a predicted binding site for TALE1Xam in its promoter region. This gene encodes for a Heat Shock Transcription Factor B3 (HsfB3) and likely acts a transcriptional repressor. HsfB3 may constitute a new type of susceptibility gene activated by a TAL effector that manages to be sufficient for symptom development without suppressing defense responses in the plant. mRNA of Cassava stems inoculated with a non-pathogenic (ORST4) and pathogenic (+TALE1Xam) strain of Xanthomonas axonopodis pv. Manihotis, tissues collected at 0, 5 and7 days post-inoculation, 2 technical replicates used
Project description:microRNAs can play a crucial role in stress response in plants, including biotic stress. Some miRNAs are known to respond to bacterial infection. This work has addressed the role of miRNAs in Manihot esculenta (cassava)-Xanthomonas axonopodis pv. manihotis (Xam) interaction. Illumina sequencing was used for analyzing small RNA libraries from cassava tissue infected and non-infected with Xam. Cassava variety MBRA685 (resistant to Xam-CIO151) Six-week-old plants were inoculated with 36h-old cultures of the aggressive Xanthomonas axonopodis pv. manihotis strain CIO151 in both leaves and stems. Leaves were inoculated by piercing six holes in the mesophyll and placing a 5µL drop of a liquid Xam-MgCl2 culture calibrated at OD600nm = 0.002 (1 x108cfu/ml). Two leaflets per leaf and three leaves per plant were inoculated. Stems were inoculated by puncture in the stems as described previously (24). At least three plants per collection time were inoculated. Leaves and stems were collected from inoculated plants (0 hours post inoculation -hpi, 6hpi, 24hpi, 2 days post-inoculation -dpi, 5dpi, 7dpi and 15dpi) and non-inoculated plants. RNA extractions were made using a LiCl-acid phenol:chloroform method.
Project description:- Identification of proteins whose expression was affected by three putative methyltransferases in Xanthomonas axonopodis pv. glycines str. 8ra - Shotgun proteomic analysis was used - Four strains were used with three biological replicates (total 12 samples). One is the wildtype carrying an empty vector and three are the wildtype is overexpressing AOY63480 (XAR_0638), AOY64271 (XAR_2195: XgMT2), or AOY60995 (XAR_3653: XgMT3). AOY63480, AOY64271, and AOY60995 are putative methyltransferases.
Project description:- Identification of proteins whose expression was affected by lcrX knockout and LcrX-overexpressing strains in Xanthomonas axonopodis pv. glycines str. 8ra - Shotgun proteomic analysis was used - Four strains were used with three biological replicates (total 12 samples). Two samples are the wildtype strains carrying an empty vector: One (XagW+V) for comparison with lcrX-KO strain and the other (XagW_V) for comparison with LcrX-overexpressing strain. The third sample is lcrX-KO strain (Xag2894KO). The last sample is LcrX-overexpressing strain (Xag2894OE).
Project description:Xanthomonas axonopodis pv. manihotis (Xam) is a gram negative bacterium causing Cassava Bacterial Blight (CBB), an important limitation for cassava production. The genetic bases underlying cassava resistance and susceptibility to different Xam strains are currently unknown. To identify genes and pathways important for the interaction, we used RNA-seq data to study transcriptomic changes in cassava plants inoculated with the non-pathogenic Xam strain, (ORST4) and a pathogenic strain, ORST4 transformed with the TAL effector TALE1Xam (ORST4+TALE1Xam). This analysis revealed that transcriptomic responses to both strains were very similar and were dominated by the induction of genes related to photosynthesis and phenylpropanoid biosynthesis and the down-regulation of genes related to jasmonic acid signaling, features possibly related to defense responses. Among the genes induced exclusively in cassava plants inoculated with ORST4 + TALE1Xam we found one gene containing a predicted binding site for TALE1Xam in its promoter region. This gene encodes for a Heat Shock Transcription Factor B3 (HsfB3) and likely acts a transcriptional repressor. HsfB3 may constitute a new type of susceptibility gene activated by a TAL effector that manages to be sufficient for symptom development without suppressing defense responses in the plant.
Project description:Quorum sensing (QS) in Xanthomonas axonopodis pv. citri, the causal agent of citrus canker, is mediated by a diffusible signal factor (DSF). QS is required for the full virulence of X. axonopodis pv. citri in planta. Mutations in rpfF, rpfC and rpfG, the core genes of QS, decreased the production of extracellular proteases and bacterial motility. Comparison of the transcriptomes of QS mutants with that of the wild type stain revealed that QS temporally regulates the expression of a large set of genes, including genes involved in chemotaxis and flagellar biosynthesis, genes related to metabolism, genes encoding virulence traits such as type II secretion system substates, type III secretion system and effectors. Cross talk between the QS regulon and the HrpG regulon has also been identified by 62 common genes shared by both regulons. The temporal regulation of the QS regulon and cross talk with the HrpG regulon suggest the important role of QS in citrus canker infection, including attachment, invasion and growth in host apoplast. Three mutants and two time-points experiment. Four biological and dye-swap replicates of each strain per each time-point were used. In total, there were two datasets of the rpfF mutant: 1) rpfF mutant vs. wild type strain at 11 h, and 2) rpfF mutant vs. wild type strain at 25 h; two datasets of the rpfC mutant: 1) rpfC mutant vs. wild type strain at 11 h, and 2) rpfC mutant vs. wild type strain at 25 h; and two datasets of the rpfG mutant: 1) rpfG mutant vs. wild type strain at 11 h, and 2) rpfG mutant vs. wild type strain at 25 h.