Transcriptome analysis of rice ABA deficient mutant Osaba1-1 and wild-type before and 72h after Xanthomonas oryzae pv. oryzae (Xoo) infection
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ABSTRACT: ABA deficient mutant Osaba1-1 exhibits great resistance to Xanthomonas oryzae pv. oryzae (Xoo) infection. To investigate gene expression profile changes at whole genome level between Osaba1-1 and wild-type (Nipponbare) rice during Xoo infection, we employed microarray expression profiling as a discovery platform. Osaba1-1 and wild-type rice plants about 6.5 leaf stage were used in this experiment. For Xoo inoculation, tips (about 3cm) of the fifth and sixth fully expanded leaves were cut off, and then immersed into Xoo (PXO99 strain) inoculum (suspended in sterile distilled water containing 10mM MgCl2, OD≈0.5) immediately for about fifteen seconds. Inoculated rice leaves were collected (approximately 2 cm leaf fragment from the inoculation site) at 0h and 72h post inoculation. Three independent replicate samples were collected at each time point for microarray.
Project description:The transcriptomic modulations leading to defense response in rice one hour after inoculation by Xanthomonas oryzae pv oryzae. Xoo and mock inoculated plant of cultivars IET8585 (bacterial leaf blight resistant) and IR-24 (bacterial leaf blight susceptible) were compared.
Project description:Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial blight disease, is one of the major threats to rice productivity. Yet, the molecular mechanism of rice-Xoo interaction is elusive. Here, we report comparative proteome profiles of Xoo susceptible (Dongjin) and resistant (Hwayeong) cultivars of rice in response to two-time points (3 and 6 days) of Xoo infection. Low-abundance proteins were enriched using a protamine sulfate (PS) precipitation method and isolated proteins were quantified by a label-free quantitative analysis, leading to the identification of 3846 protein groups. Of these, 1128 proteins were significantly changed between mock and Xoo infected plants of Dongjin and Hwayeong cultivars. Based on the abundance pattern and functions of the identified proteins, a total of 23 candidate proteins were shortlisted that potentially participate in plant defense against Xoo in the resistant cultivar. Of these candidate proteins, a mitochondrial arginase-1 showed Hwayeong specific abundance and was significantly accumulated following Xoo inoculation. Overexpression of arginase-1 in susceptible rice cultivar (Dongjin) resulted in enhanced tolerance against Xoo as compared to the wild-type (WT). In addition, expression analysis of defense-related genes encoding PR1, glucanase I, and chitinase II by qRT-PCR showed their enhanced expression in the overexpression lines as compared to WT. Mitochondrial localization of the selected arginase was further confirmed by fluorescent microscopy using GFP-tagged arginase. Taken together, our results uncover the proteome changes in the rice cultivars and highlight the functions of arginase in plant defense against Xoo.
Project description:Xanthomonas oryzae pv. oryzae (Xoo) is a rice pathogen causing bacterial blight, which outbreaks in most rice cultivating countries and reduces yield up to 50% due to no effective pesticide. Urgent responses of Xoo upon the initial contacts with rice at infection site are essential for pathogenesis. We studied the time-resolved gene expression of both transcriptome and proteome in the pathogenicity-activated Xoo cells with an in vitro assay system. Genes related to cell mobility, inorganic ion transport and effectors are early response genes to help Xoo cells invade into damaged rice leaf tissues, obtain rare cofactors, and evade rice immune responses. Although the time-resolved gene expression pattern of Xoo is conserved in both mRNA and protein, there are varied time gaps in genes between the expression peaks of mRNA and protein, which implies there is an additional translational selection step of specific mRNAs for rapid translation. The expression pattern of genes from a polycistronic mRNA in the same gene cluster is strictly conserved. The time-resolved gene expression study of Xoo in both transcriptome and proteome provides a valuable information about the pathogenic responses of Xoo at the initial stage of Xoo-rice interaction.
Project description:Previously, we successfully introduce the bacterial blight resistance trait from Oryza meyeriana into O. sativa using asymmetric somatic hybridization with O. meyeriana as the donor species. After years of breeding, a progeny named Y73 was generated with recurrent parent O. sativa L. ssp. japonica cv. Dalixiang, and it shows high resistance to broad-spectrum of bacterial blight pathogens Xanthomonas oryzae pv. Oryzae (Xoo). However, the resistance mechanism of Y73 is remain undiscovered. To provide insights into the high resistance phenotype of these plants, we examined the transcriptome response in leaves of Y73 to the bacterial blight infection in this study. Xoo inoculated and mock inoculated rice plants were grown in growth room and the global analysis of gene expression events in rice leaves at 24 hours post inoculation (hpi) were analyzed using Affymetrix Rice GeneChip microarrays. We used microarrays to detail the global programme of gene expression underlying Xoo infection in rice Y73.
Project description:Previously, we successfully introduce the bacterial blight resistance trait from Oryza meyeriana into O. sativa using asymmetric somatic hybridization with O. meyeriana as the donor species. After years of breeding, a progeny named Y73 was generated with recurrent parent O. sativa L. ssp. japonica cv. Dalixiang, and it shows high resistance to broad-spectrum of bacterial blight pathogens Xanthomonas oryzae pv. Oryzae (Xoo). However, the resistance mechanism of Y73 is remain undiscovered. To provide insights into the high resistance phenotype of these plants, we examined the transcriptome response in leaves of Y73 to the bacterial blight infection in this study. Xoo inoculated and mock inoculated rice plants were grown in growth room and the global analysis of gene expression events in rice leaves at 24 hours post inoculation (hpi) were analyzed using Affymetrix Rice GeneChip microarrays. We used microarrays to detail the global programme of gene expression underlying Xoo infection in rice Y73. To find out pathways and genes involved in its high and board-spectrum resistance, microanalysis were carried out on Y73 after Xoo infection at 24 hours post inoculation (hpi). Three independant replicates were perfomed for each treatments.
Project description:X. oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight of rice. X. oryzae pv. oryzicola (Xoc) is the causal agent of bacterial streak of rice. Fourteen day old rice leaves were inoculated with one of five strains of Xanthomonas oryzae. Seven strains of Xoo were used; three wild type strains (PXO99A, T7174, and PXO86) and strains PXO99AME7, which has a nonfunctional type III secretion system and is non-pathogenic, , PXO99AME1, a pthXo6 and avrXa27 double mutant, PXO99ME2, a pthXo1 mutant, and PXO99ME5, a reduced virulence strain with uncharacterized mutation in a TAL effector. One strain of Xoc (BLS303) was tested. Controls include an inoculation with water (MOCK) and no inoculation. T7174 is our label for the Japanese isolate MAFF311018. Third leaves are inoculated with a needless syringe at adjacent sites along the upper leaf blade. Six leaves from separate plants are pooled. RNA samples were collected 24 h after treatment. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Ginny Antony. The equivalent experiment is OS66 at PLEXdb.]
Project description:Xanthomonas oryzae pv. oryzae (Xoo) causes the bacterial leaf blight of rice, which leads to as much as 50% yield losses. To understand the landscape of virulence mechanisms, we constructed in planta transcriptional profiling of Xoo KACC10331 using RNA-seq. Three in planta transcriptome of Xoo KACC10331 derived from infected rice leafs were compared to three in vitro data from rich media. To obtain differentially expressed genes, we used the DEGseq package with MA-plot-based method in the R statistical environment and identified 2,094 transcripts that were significantly altered.
Project description:ABA deficient mutant Osaba1-1 exhibits great resistance to Xanthomonas oryzae pv. oryzae (Xoo) infection. To investigate gene expression profile changes at whole genome level between Osaba1-1 and wild-type (Nipponbare) rice during Xoo infection, we employed microarray expression profiling as a discovery platform.
Project description:TITLE: Transcriptional profiling of Rgene-mediated responses in rice PROJECT DESCRIPTION: The dominant gene Xa7 and the recessive gene xa5 of rice confer resistance to several races of the bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo). To reveal the modes of action and the defense responses these genes initiate, we decided to obtain the global transcriptional profiles of the rice cultivars IRBB7, IRBB5 (which harbor Xa7 and xa5, respectively) and IR24 undergoing early infection by the Xoo Race 2 strain PXO86. Both IRBB7 and IRBB5 are resistant to PXO86 (which carry the corresponding avirulence genes avrXa7 and avrxa5), whereas IR24 is susceptible. We inoculated by vacuum infiltration the three rice cultivars ten days after seed germination (or 2 weeks after sowing) and collected inoculated tissue at 5 different timepoints within the first day after inoculation. The transcriptional profiles obtained will provide valuable insight into the similarities and differences between incompatible interactions mediated by a dominant and a recessive Rgene, in comparison to a compatible interaction. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, David O Nino-Liu. The equivalent experiment is OS4 at PLEXdb.]
Project description:Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) are important bacterial pathogens of the worldwide staple and grass model, rice. Xoo invades rice vascular tissue to cause bacterial leaf blight, a serious disease of rice throughout the world. Xoc colonizes the parenchyma tissue to cause bacterial leaf steak, a disease of emerging importance. We have designed oligonucleotide probes (50-70-mers) represented 2,858 Xoo genes and 1,816 Xoc genes annotated by The Institute for Genomic Research (TIGR). To validate the Xo arrays, self-hybridization samples and tests of the non-specific hybridization using randomly spotted oligonucleotides corresponding to the hygromycin phosphotransferase gene (hph), and blank spot and of the correlation coefficient between biological replicates as well as between duplicate spots revealed that the data generated from our oligo array were highly reliable and consistent. To demonstrate application of Xo array, we performed expression profiling experiments on arrays hybridized with RNA of Xoo and Xoc grown in the two different nutrient-condition media. Several sets of genes involved in bacterial movement, chemotaxis, and hrp genes differentially express in response to different treatment. Due to comprehensive views of microarray study, extended biological events of plant-bacteria interaction was described. This publicly available microarray for Xanthomonas oryzae (Xo) is an enabling resource for a large and international community of scientists to better understand not only Xo biology but also many other Xanthomonas species that cause significant losses on crops. Keywords: Media condition response