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: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. Experiment Overall Design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during bacterial pathogen infection. We used two contrasting rice genotypes (IET8585 (Ajaya) blb resistant IR24 blb susceptible) differing in bacterial disease response. Plants were grown growth chambers and inoculated with bacterial pathogen on 18th DAS. Leaf sampling was done in both un-inoculated and inoculated plants at 3 time points. Two replications of microarray experiments were carried out by hybridizing the resistant samples against the susceptible samples.
Project description:Rice Xa21 resistance gene, which encodes a protein with predicted leucine-rich repeat (LRR), transmembrane, juxtamembrane, and intracellular kinase domains, conferred immunity to diverse strains of Xanthomonas oryzae pv. oryzae (Xoo). We generated Xa21 plant on TP309 background (Oryza Sativa Japonica). Systemic Acquired Resistance (SAR) in plants confers durable broad-spectrum resistance to pathogens and requires a phytohormone, salicylic acid (SA). Arabidopsis NPR1/NIM1 is a key regulator of the SAR response. Recently, we found that rice NPR1 homolog 1 (NH1) mediated enhanced resistance responses for Xoo (Chern et al., 2005b). We further investigated relating pathways in rice by identifying proteins that interact with NH1. One of them, constitutive over-expression of NH1 mediated negative regulator of resistance (NRR) gene caused enhanced susceptibility to Xoo , indicating that this gene product negatively affects to basal resistance response (Chern et al., 2005a). To dissect defense responses for rice bacterial blight pathogen, we planed microarray using two resistant mutant named with Xa21-TP309, NH1ox and one super-susceptible mutant (NRRox) before pathogen inoculation and one day post pathogen inoculation. Keywords: Biotic stress response
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: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: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:Yield loss in crop plants due to biotic stresses is a major problem and pyramiding of R genes is often suggested for sustained and durable resistance against target pests. Information is available for single R gene interaction in rice and other crop plants, but not much data is available for multiple R gene interaction against multiple pathogens/pests. In this study we carried out transcriptional analysis of two rice lines introgressed with either R gene against bacterial blight and gall midge or, against bacterial blight and fungal blast. The gene expression changes were investigated through microarray and the expression pattern upon co-infection with multiple pathogens was analyzed to study the synergistic effect of R gene mediated defense responses as well as to explore the possibility of any antagonism between the R genes as defense pathway employed due to R gene mediated resistance varies as per the attacking pathogen/pest. Keywords: Expression profiling by array