Transcriptome study of rice early response to rice blast fungus
ABSTRACT: Rice blast disease is a major threat to rice production worldwide, but the mechanisms underlying rice resistance to the causal agent Magnaporthe oryzae remain elusive. In this whole-genome transcriptome study of rice early defense response to M. oryzae, we applied Affymetrix Rice Genome Genechip to compare the compatible and incompatible rice-M. oryzae interactions in 24 hours post-inoculation. Leaf samples were harvested from three biological replicates of fungal- and mock-inoculated seedlings at 24 hours post-inoculation, from which RNA were extracted and analyzed with Genechip Rice Genome Array.
Project description:Magnaporthe oryzae is the causative agent of the rice blast, the most relevant rice disease worldwide. To date expression analysis on rice infected with Magnaporthe oryzae have been carried out only with the strains FR13 (leaf) and Guy 11 (root). However different strains of Magnaporthe are present in the environment leading to different rice responses at molecular level. To gain more insight on the unknown molecular mechanisms activated by different Magnaporthe strains during rice defense, a global expression analysis was performed by using the GeneChip® Rice Genome Array. To identify rice genes differentially regulated upon infection by Magnaporthe isolates, inoculation with different strains were performed and samples were collected 24 hours post infection. RNA were obtained from leaf samples after inoculation of rice 2 week-old plantlets with the following strains: rice isolates Magnaporthe oryzae FR13 and CL367, non-adapted strain BR32, isolated from wheat, and Magnaporthe grisea BR29 isolated from crabgrass. Treated and control (mock) rice leaves (cv. Nipponbare) were collected 24 hours post inoculation. Three biological replicates for each interaction type and the corresponding mock were extracted and analysed independently with the GeneChip® Rice Genome Array.
Project description:Rice blast disease is a major threat to rice production worldwide, but the mechanisms underlying rice resistance to the causal agent Magnaporthe oryzae remain elusive. In this whole-genome transcriptome study of rice early defense response to M. oryzae, we applied Affymetrix Rice Genome Genechip to compare the compatible and incompatible rice-M. oryzae interactions in 24 hours post-inoculation. Overall design: Leaf samples were harvested from three biological replicates of fungal- and mock-inoculated seedlings at 24 hours post-inoculation, from which RNA were extracted and analyzed with Genechip Rice Genome Array.
Project description:Magnaporthe oryzae causes rice blast, the most devastating foliar fungal disease of cultivated rice. During disease development the fungus simultaneously maintains both biotrophic and necrotrophic growth corresponding to a hemi-biotrophic life style. The ability of M. oryzae to also colonize roots and subsequently develop blast symptoms on aerial tissue has been recognized. The fungal root infection strategy and the respective host responses are currently unknown. Global temporal expression analysis suggested a purely biotrophic infection process reflected by the rapid induction of defense response-associated genes at the early stage of root invasion and subsequent repression coinciding with the onset of intracellular fungal growth. The same group of down-regulated defense genes was increasingly induced upon leaf infection by M. oryzae where symptom development occurs shortly post tissue penetration. Our molecular analysis therefore demonstrates the existence of fundamentally different tissue-specific fungal infection strategies and provides the basis for enhancing our understanding of the pathogen life style. Experiment Overall Design: We investigated global transcriptome response overtime of Mock- and M. oryzae inoculated rice root tissue in vitro. Two independant replicates were perfomed for each treatments and samples were collected at 2, 4 and 6 days post-inoculation.
Project description:In order to understand the mechanisms of Drought induced susceptibility (DIS) we’ve conducted a dual RNAseq experiment on rice infected tissues by Magnaporthe oryzae. At 4 days post inoculation tissues have been collected on mock inoculated and M. oryzae inoculated plants. Rice were conducted under two type of water regime: DIS Drought during three days before inoculation, NoDIS no drought before inoculation. RNAseq was conducted both on rice and fungal RNA. Overall design: shoot tissus mRNA 21-day old rice plant were generated by deep sequencing. Three samples per conditions, Four conditions: NoDIS Mock, NoDIS Inoc, DIS Mock, DIS Inoc. NoDIS = plant were conducted with a normal water regime. DIS = plant received no watering during three days before inoculation. Mock = Plant inoculated with control solution (gelatin 0,5%). Inoc = Plant inoculated with Magnaporthe oryzae isolate Fr13 with gelatin 0,5%.
Project description:Cellulase, a Type II secretion system secreted protein of Xanthomonas oryzae pv. oryzae (Xoo; the casual of bacterial leaf blight of rice) is a potent inducer of rice defense responses such as hypersensitive response like reactions (HR), callose depositions, cell death associated with nuclear fragmentations and impart functional resistance against further Xoo inoculation In order to understand the molecular events associated with cellulase induced HR in rice, whole genome transcriptional profiling was performed using Affymetrix Rice GeneChips Keywords: Expression profiling of a hypersensitive reaction like response Leaves of 20 days old green house grown susceptible rice cultivar (Taichung Native-1; TN-1) were infiltrated with either 30-40μl of purified Xoo cellulase (5μg/ml) or with buffer (10mM potassium phosphate buffer pH 6.0) alone (as described in Jha et al. 2007; MPMI vol 20, pp 31-40). The plants were shifted to a growth chamber (28oC; 80% relative humidity; 12/12h light/dark cycle) 48 hours before the treatment. 20-30 leaf pieces covering the infiltrated zone from each of the treatments were harvested 12 h after infiltration. Total RNA isolated from the pooled samples was subjected for expression analysis using Affymetrix GeneChip System. The experiment was repeated with three different biological replicates using RNA isolated from three batches of rice leaves treated with the freshly purified Xoo cellulase and the buffer
Project description:In order to understand the mechanisms of Nitrogen induced susceptibility (NIS) we’ve conducted a dual RNAseq experiment on rice infected tissues by Magnaporthe oryzae. At 0 day post inoculation and 2 days post inoculation tissues have been collected on mock inoculated and M. oryzae inoculated plants. Rice were conducted under two type of nitrogen fertilization: 0N all fertilization but nitrogen, 1N all fertilization and NH4NO3. The fertilization was applied one day before inoculation. RNAseq was conducted both on rice and fungal RNA. Overall design: shoot tissus mRNA 28-day old rice plant were generated by deep sequencing. Three samples per conditions, Four conditions: 0N Mock, 0N Inoc, 1N Mock, 1N Inoc. 0N = plant fertilized one day before inoculation without nitrogen. 1N = plant fertilized one day before inoculation with NH4NO3. Mock = Plant inoculated with control solution (gelatin 0,5%). Inoc = Plant inoculated with Magnaporthe oryzae isolate Guy11 with gelatin 0,5%.
Project description:Analysis of transgenic rice plants overexpressing the rice WRKY transcription factor OsWRKY53 or its phospho-mimicking mutant (OsWRKY53SD). Results provide insight into the roles of OsWRKY53 and its phosphorylation in the basal defense signaling against the rice blast fungus. Expression profiling in wild-type, OsWRKY53- or its phospho-mimicking mutant-overexpressing rice leaves infected with or without Magnaporthe Oryzae was analyzed using one-color method with four biological replicates.
Project description:Analysis of transgenic rice overexpressing OsWRKY28, a WRKY type transcription factor. Results provide insight into the role of OsWRKY28 in the defense signaling against rice blast fungus. Expression profiling in wild-type and OsWRKY28 overexpressing rice leaves infected with or without Magnaporthe Oryzae was analyzed using one-color method with three biological replicates.
Project description:To investigate the responses of resistance gene Pi54 at transcriptome level in blast resistant transgenic rice line TP-Pi54 during infection by Magnaporthe oryzae, we studied the co-expression analysis using microarray along with susceptible non-transgenic line Taipei 309 (TP). Suitable controls for both lines were used. The comparative analysis of differentially expressed genes was conducted. Total RNA from the leaves of mock inoculated non transgenic line Taipei 309 (TP) and transgenic line (TP-Pi54) along with challenge inoculated plants were isolated at 72 hours post inoculation. The samples were analyzed in two different biological replications (A and B) making total eight samples.
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.