Project description:Lesion mimic mutants in rice are widely known as spotted leaf (spl) mutants, of which several genotypes exhibit enhanced resistance to different races of Magnaporthe grisea. Besides naturally occurring spotted leaf mutants, tissue culture-induced reverse genetic repositories also act as sources of lesion mimic mutants in rice. We systematically evaluated a large collection of Tos17 mutant panel lines, developed and maintained at the National Institute of Agrobiological Sciences, Tsukuba, Japan, for their reaction to three different races of M. grisea and identified a lesion mimic mutant, NF4050-8, that showed lesions similar to naturally occurring spl5 mutant and enhanced resistance to all three blast races tested. Microarray analysis of ~44,000 rice genes in NF4050-8 with Nipponbare as control during the progressive lesion appearance stage revealed significant up-regulation of numerous defense/pathogenesis-related genes as well as several WRKY domain-containing genes and down-regulation of haem peroxidase gene. Subsequent real-time PCR analysis of WRKY45 and PR1b genes in NF4050-8 and spl5 suggested possible constitutive activation of a defense signaling pathway downstream of Salicylic Acid (SA) but independent of NH1 in these mutant lines of rice.
Project description:Lesion mimic mutants in rice are widely known as spotted leaf (spl) mutants, of which several genotypes exhibit enhanced resistance to different races of Magnaporthe grisea. Besides naturally occurring spotted leaf mutants, tissue culture-induced reverse genetic repositories also act as sources of lesion mimic mutants in rice. We systematically evaluated a large collection of Tos17 mutant panel lines, developed and maintained at the National Institute of Agrobiological Sciences, Tsukuba, Japan, for their reaction to three different races of M. grisea and identified a lesion mimic mutant, NF4050-8, that showed lesions similar to naturally occurring spl5 mutant and enhanced resistance to all three blast races tested. Microarray analysis of ~44,000 rice genes in NF4050-8 with Nipponbare as control during the progressive lesion appearance stage revealed significant up-regulation of numerous defense/pathogenesis-related genes as well as several WRKY domain-containing genes and down-regulation of haem peroxidase gene. Subsequent real-time PCR analysis of WRKY45 and PR1b genes in NF4050-8 and spl5 suggested possible constitutive activation of a defense signaling pathway downstream of Salicylic Acid (SA) but independent of NH1 in these mutant lines of rice. We used Agilent rice oligo microarrays to identify putative defense/pathogenesis-related genes. Leaf tissues of the rice genotypes Nipponbare and NF4050-8 were used in the study. Two replications of microarray experiments were carried out by hybridizing the cRNA from control and progressive lesion appearance stage on 4 x 44k microarray.
Project description:The rice lesion mimic, spotted leaf 5 (spl5), created by γ-ray radiation, has spontaneous HR-like lesions on its leaves and shows enhanced resistance to rice blast and bacterial blight pathogens. Some genes were differentially expressed in this mutant compared with its WT control ZF802, and these genes were also associated with some important signaling pathways, such as defense response, oxidation-reduction process and stress response. We analyzed the transcriptional profiling of spl5 mutant and WT using the microarray, in order to reveal the signal pathway of SPL5 gene in regulation of disease resistance.
Project description:The rice lesion mimic, spotted leaf 5 (spl5), created by M-NM-3-ray radiation, has spontaneous HR-like lesions on its leaves and shows enhanced resistance to rice blast and bacterial blight pathogens. Some genes were differentially expressed in this mutant compared with its WT control ZF802, and these genes were also associated with some important signaling pathways, such as defense response, oxidation-reduction process and stress response. We analyzed the transcriptional profiling of spl5 mutant and WT using the microarray, in order to reveal the signal pathway of SPL5 gene in regulation of disease resistance. Rice leaves were selected at lesion stages of spl5 mutant for RNA extraction and hybridization on Affymetrix microarrays. The lesions in rice leaves were belong to HR phenotype, which was one of the important reasons for rice disease resistance. In order to realize which genes were associated with the degree of lesions and mediated the disease resistance, we put the leaves of spl5 mutant into two categories, based on the degree of lesion formation: few lesions (FL), leaf area with 10-20% lesions and many lesions (ML), leaf area with 70-80% lesions.
Project description:The allene oxide synthase (AOS) branch and the hydroperoxide lyase (HPL) branch of the oxylipin pathway function in plant responses to diverse stresses and have potential cross-talks between each other in the biosynthesis and signaling regulation, but there is still an absence of direct evidence and detailed information about this communication. Here, we identified and characterized a jasmonates acid (JA) overproduction mutant, cea62, by screening the Constitutive Expression of AOS gene (cea) from rice T-DNA insertion mutant library. Map-based cloning was used to isolate the target gene as the hydroperoxide lyase OsHPL3 gene. The gene expression, HPL enzyme activity and its resulting products, (E)-2-hexenal, were all depleted in the cea62 mutant, which resulted in dramatic JA overproduction and activation of JA signaling in the mutant. Consistent with the formation of the lesion mimic phenotype and the timing of the induction for some defense responsive genes, the activation of JA biosynthesis and signaling was regulated in a developmental way, just as the way by which OsHPL3 was regulated in the wild type plant. Microarray data showed that the JA-governed defense response was greatly activated in the cea62 mutant plant and the cea62 plant obtained enhanced resistance to the bacterial blight pathogen Xanthomonasoryzaepvoryzae (Xoo) T1 strain. Wounding response was attenuated in the cea62 mutant at an early developmental stage, while it was partially recovered when JA levels were elevated at a later developmental stage in the cea62 mutant. But, the wounding response was not altered at different developmental stages in the wild type plant. These findings suggest that these two branches of the oxylipin pathways crosstalked in the biosynthesis and signaling pathways and cooperated with each other to function in diverse stress responses. We compared the gene expression profile in leaf tissues of the wild-type plant and the cea62 mutant after lesion mimic phenotype appeared two months after sowing. Total RNAs were extracted from leaf blades from the rice (Oryza sativa L.) wild-type Nipponbare plant and from leaf blades of the rice (Oryza sativa L.) cea62 mutant in the Nipponbare (ssp japonica) background at two months after sowing. Three replicates of the cea62 mutant and wild type were performed.
Project description:Overexpression of programmed cell death 5 gene (PDCD5) in tumor cells enhances apoptosis triggered by growth factor or serum deprivation, and overexpression of its homolog, OsPDCD5, induces the early death of transgenic plants. In this work, a system of inducible OsPDCD5 expression using a heat shock promoter was developed to study PCD in rice at different developmental stages.The results showed that in three-leaf aged and older seedlings, OsPDCD5 could independently induce PCD. In altered plants, OsPDCD5 expression caused lesion mimic phenotype, abnormal leaf morphology, nuclear condensation, DNA fragmentation, and H2O2 production. But two-leaf aged and younger seedlings seedlings showed no visibly morphological phenotype after OsPDCD5 expression, suggested that young seedlings possessed some mechanism inhibiting OsPDCD5 induced PCD.
Project description:affy_riz_2011_7 - affy_riz_2011_7 - The Bacterial Leaf Blight disease of rice is due to Xanthomonas oryzae pv. oryzae. As for many pathogenic bacteria, it relies on a type 3 secretion system (TTSS) that is devoted to the injection of type 3 effectors (T3Es) into the eukaryotic host cell. These proteins are meant to suppress host basal defense responses and/or mimic some host regulatory function promoting bacterial survey in the plant. During an incompatible interaction, T3Es may act as Avr proteins and stimulate Effector-Triggered-Immunity. We aim at evaluating the transcriptomic response of rice leaves challenged with avirulent strains of Xoo BAI3 and MAI1 on resistant lines IR64 and IRBB4 versus the reference susceptible rice line Nipponbare. In addition, we investigated the transcriptomic response of rice leaves upon inoculation of an XoohrcC mutant strain affected in the production of a functional TTSS.-The goal of the experiment is to characterize the rice leaf transcriptome response, upon the inoculation of susceptible and resistant rice leaves 24 hours post-infection. To that end, the experimental design includes the inoculation of susceptible Nipponbare rice leaves with Xoo strains BAI3 (race A1) and MAI1 (race A3), that will be compared to the response of resistant lines IRBB4 and IR64 rice lines. In addition, Nipponbare rice leaves will also be challenged with the BAI3hrcC mutant that is affected in the production of a functional TTSS.
Project description:The angle of rice leaf inclination is an important agronomic trait and closely related to the yield and architecture of crops. Through genetic screening, a rice gain-of-function mutant leaf inclination1, lc1, was identified . Phenotypic analysis confirmed the exaggerated leaf angels of lc1 due to the stimulated cell elongation at the collar.In this series, we compare the transcriptome of zhonghua11 and lc1 collar.