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: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:African Xanthomonas oryzae pv. oryzae strains seem most closely related to and share several genetic features with pathovar oryzicola despite causing symptoms of bacterial leaf blight. The ability of most Xanthomonas plant pathogenic bacteria to infect their host relies on the action of a specific family of type III effectors called the TAL effectors. These microbial transcription factors are injected into the plant and manipulate the host transcriptome upon binding to the promoters of plant genes. The genes whose induction is of benefit to the pathogen are called susceptibility genes. RNA profiling experiments in rice using the Malian Xoo strain MAI1 and in silico prediction of TAL effector binding sites were carried out to identify candidate targets of TalB, revealing OsTFX1, a bZIP transcription factor previously identified as a bacterial blight S gene, and OsERF#123, which encodes a subgroup IXc AP2/ERF transcription factor.
Project description:An indica rice cultivar IET8585 (Ajaya), resists diverse races of the Xanthomonas oryzae pv oryzae (Xoo) pathogen attack, and is often cultivated as bacterial leaf blight (blb) resistant check in India. Earlier we reported a recessive blb resistance gene mapped to the long arm of chromosome 5 in IET8585. To further understand the mechanism of recessive and durable resistance response, two indica rice genotypes namely, i) IET8585 (Ajaya), a disease resistant indica veriety from India and ii) IR24, a bacterial leaf blight disease susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under inoculated and un-inoculated conditions during seedling stage. Keywords: Bacterial leaf blight disease resistance mechanism
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:Overexpression of a transcription factor OsEREBP1 results in attenuation of disease symptoms upon infection with bacterial pathogen Xanthomonas oryzae pv. oryzae and tolerance to drought stress in transgenic rice plants. Microarray analysis was performed to identify genes regulated by the rice transcription factor OsERBP1.
Project description:Transcriptional profiling of Oryza sativa japonica Nipponbare roots after 14 days post infection with Xanthomonas oryzae pv. oryzae strain PXO99 , the goal is to understand the transcriptomic response of rice roots to colonization by bacterial pathogen
Project description:Vascular plant diseases, such as rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) and crucifer black rot caused by Xanthomonas campestris pv. campestris (Xcc), cause huge yield loss of crops worldwide. However, how plants operate vascular defense against these obligate pathogens remains elusive. In this study, we used both Arabidopsis and rice pathosystems to address the long-standing question. We found that the loss of function mutation of Arabidopsis mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP1) lost the non-host resistance to Xoo and supported Xoo to grow in the leaf veins, which also enhanced susceptibility to Xcc. MKP1 regulates the MPK3-mediated phosphorylation of the transcription factor MYB4 that functions in vascular lignification. Importantly, the MKP-MAPK cascade-mediated lignin biosynthesis is also conserved in rice through regulating OsMYB102 and OsMYB108, which control rice vascular resistance to adapted Xoo. Interestingly, the Arabidopsis and rice mutants enhanced resistance to the mesophyll cell pathogens most likely through upregulating salicylic acid biosynthesis, Pseudomonas syringae (P. syringae) and Xanthomonas oryzae pv. oryzicole (Xoc), respectively; strongly suggesting that this immune mechanism is likely specific to the obligate vascular pathogens. Therefore, our study uncovers a previously unrecognized vascular-specific and lignin-based immune mechanism, shedingshedding new sight on tissue-specific immunity in plants, as well as providing a practical approach for improvement of disease resistance against vascular pathogens in crops
Project description:Endogenous small RNAs are newly identified players in plant immune responses, yet their roles in rice (Oryza sativa) responding to pathogens are still less understood, especially for pathogens that can cause severe yield losses. Here, we examined the small RNA expression profiles of rice leaves at 2, 6, 12, and 24 hours post infection of Xanthomonas oryzae pv. oryzae (Xoo) virulent strain PXO99, the causal agent of rice bacterial blight disease. Dynamic expression changes of some miRNAs and trans-acting siRNAs (ta-siRNAs) were identified, together with a few novel miRNA targets, including a disease resistance gene targeted by osa-miR159a.1. Coordinated expression changes were observed among some miRNA and ta-siRNAs in response to Xoo infection, with small RNAs exhibiting the same expression pattern tended to regulate genes in the same or functional correlated signaling pathways, including auxin and GA signaling pathways, nutrition and defense related pathways, etc. Highly abundant small RNAs with pathogen-responsive expression changes were identified from the exonic region of a protein-coding gene, which may present a new class of functional small RNAs. These findings reveal the dynamic and complex roles of small RNAs in rice-pathogen interactions, and identified new targets for regulating plant immune responses. Examination of the small RNA expression profiles of rice leaves at 2, 6, 12, and 24 hours post infection of Xanthomonas oryzae pv. oryzae (Xoo) virulent strain PXO99