Project description:In this study, we used dual RNA-sequencing to profile FHB-resistant AC Emerson, FHB-moderately AC Morley, and FHB-susceptible CDC Falcon winter wheat cultivars prior to and in response to Fusarium graminearum at 7 days post inoculation. Differential expression analyses revealed distinct defense responses between resistant and susceptible wheat cultivars including increased mechanical defense through lignin biosynthesis and increased deoxynivalenol (DON) detoxification through UDP-glycosyltransferase activity in resistant cultivars. Further, differential expression analysis in F. graminearum challenging these distinct cultivars revealed changes genes involved in trichothecene mycotoxin biosynthesis.
Project description:The RNA sequencing analysis was undertaken to investigate the transcriptomic changes in adult wheat inoculated with Puccinia graminis f. sp. tritici the causal agent of stem rust disease. The project firstly aims to compare gene expression in one susceptible wheat line with two wheat lines exhibiting adult plant resistance to the stem rust. Secondly, the project aims to examine the temporal changes in gene expression in wheat after inoculation. Wheat plants was grown until maturity under greenhouse conditions. Plants were inoculated with Puccinia graminis f. sp. tritici and the flag leaf sheath sampled for RNA sequencing. The project aims to give essential insight into the adult plant resistance response in wheat to Puccinia graminis f. sp. tritici inoculation.
Project description:The fungus Puccinia striiformis f.sp. tritici (PST) is the causal pathogen of stripe rust in wheat. New highly virulent PST races appeared at the beginning of this century and spread rapidly causing significant yield losses in wheat production worldwide. Race PST-08/21 was isolated in the UK in 2008 Yr1, Yr2, Yr3, Yr4, Yr6, Yr9, Yr17, Yr27, Yr32, YrRob, YrSol. We applied the RNAseq approach to refine the gene prediction in de novo assembled PST 08/21 contigs and to determine which genes are expressed during wheat infections.
Project description:The fungus Puccinia striiformis f.sp. tritici (PST) is the causal pathogen of stripe rust in wheat. New highly virulent PST races appeared at the beginning of this century and spread rapidly causing significant yield losses in wheat production worldwide. Race PST-08/21 was isolated in the UK in 2008 Yr1, Yr2, Yr3, Yr4, Yr6, Yr9, Yr17, Yr27, Yr32, YrRob, YrSol. We applied the RNAseq approach to refine the gene prediction in de novo assembled PST 08/21 contigs and to determine which genes are expressed during wheat infections. Total RNA was extracted from a pool of stripe rust infected wheat leaves and from two biological replicates of haustoria isolates.
Project description:Stripe rust (Puccinia striiformis f. sp. tritici; Pst) and powdery mildew (Blumeria graminis f. sp. tritici; Bgt) are important diseases of wheat (Triticum aestivum) worldwide. Similar mechanisms and gene transcripts are assumed to be involved in the host defense response because both pathogens are biotrophic fungi. The main objective of our study was to identify co-regulated mRNAs that show a change in expression pattern after inoculation with Pst or Bgt, and to identify mRNAs specific to the fungal stress response. In the present study, cDNA libraries were constructed from leaves inoculated with Pst or Bgt at 0, 1, 2 and 3 days post-inoculation (dpi) with three biological replicates, and then sequenced using the Illumina HiSeq™ 2000 platform. Note: Samples in SRA were assigned the same sample accession. This is incorrect as there are different samples, hence “Source Name” was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:To test whether non-coding RNAs play roles in regulating response to powdery mildew infection and heat stress in wheat, by using Solexa high-throughput sequencing and computational analysis and experimental approach we cloned the small RNAs and identified 125 putative long npcRNAs from wheat leaves infected by preponderant physiological strain Erysiphe graminis f. sp. tritici (Egt) or by heat stress treatment. Among long non-coding RNAs, some were precursors of small RNAs such as microRNAs and siRNAs, two long npcRNAs were identified as signal recognition particle (SRP) 7S RNA variants, and three were characterized as U3 snoRNAs. Wheat long npcRNAs showed tissue dependent expression patterns and were responsive to powdery mildew infection and heat stress. Examination non-coding RNAs of 2 near isogenic lines 8866 (Susceptible) and Pm30 (Resistant) in response to powdery milew and two genotypes CK (insensitive) and TAM107 (insensitive) to heat. CK and TAM107 represent the same material in different treatments (no heat stress or 1hour after heat stress).
Project description:Fusarium Head Blight (FHB) is a disease of wheat and other cereal crops, where, among other species, Fusarium graminearum infects the wheat inflorescence. Microarrays were used to observe differential gene expression in FHB-challenged spikes of the two European winter wheat genotypes Dream (moderately resistant) and Lynx (susceptible). Plants were either inoculated with the Fusarium graminearum strain IFA 65 (IFA Tulln) (500 macroconidia/floret) or were as control plants mock treated with desalted water. The inocula were injected into four spikelets at early anthesis and spikelets were later on collected at 32 and 72 h after inoculation. Four plants were sampled per genotype/treatment/sampling date. Total RNA was extracted from collected spikelets, and microarray analysis was performed using the Affymetrix Wheat GeneChip.
Project description:Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a destructive disease of wheat worldwide. Genetic resistance is the preferred method for controlling stripe rust, of which two major types are race-specific and race non-specific resistance. Race-specific resistance includes the qualitatively inherited all-stage resistance, controlled by single major resistance (R) genes. Conversely, adult-plant resistance is race non-specific, inherited quantitatively, and is durable. Previously, we characterized the gene expression signatures involved in Yr5-controlled all-stage resistance and Yr39-controlled adult-plant resistance using the Affymetrix Wheat GeneChip. For this study, we designed and constructed custom oligonucleotide microarrays containing probes for the 116 and 207 transcripts that we had found important for the Yr5 and Yr39 resistance responses, respectively. We used this custom microarray to profile the resistance responses of eight wheat genotypes with all-stage resistance (Yr1, Yr5, Yr7, Yr8, Yr9, Yr10, Yr15, and Yr17). The aim of this analysis was to identify common and unique gene expression signatures involved in race-specific resistance accross genotypes, which were used to infer information regarding the general pathways involved in all-stage resistance. Keywords: Stress response
Project description:Aim:To characterise a recently discovered stem rust resistance locus on wheat chromosome 7AL. Transcriptome analysis by RNA-sequencing, in association with microscopic observations, was used to compare responses to the Puccinia graminis f. sp. tritici pathogen of the susceptible line Columbus, and two independent backcrossed resistant lines containing the locus, Columbus-NS765 and Columbus-NS766. Results: Microscopic observations of infected leaves revealed that the resistance conferred by the 7AL resistance locus was initiated by two days post-inoculation, upon the entry of the stem rust fungus into the plant through the stoma. Death of guard and epidermal cells adjacent to the fungal points of entry was observed to be clearly more frequent in resistant lines than in the susceptible genotype, suggesting that the resistance response is similar in all genotypes, but enhanced in the resistant lines. Transcriptomic analysis, combined with assignment of genes to wheat chromosomes, revealed a disporportionately high number of differentially expressed genes were located on chromosomes 7AL and 6A. A number of genes annotated as cysteine-rich receptor-like kinases were located on chromosome 7AL. Closer investigation indicated that the encoded proteins were in fact putative receptor-like cytoplasmic kinases (RLCKs). One of the putative RLCK genes contained a SNP marker previously shown to co-segregate with the 7AL resistance locus. The large number of differentially expressed genes on chromosome 6A indicated the presence of a large introgression on this chromosome that co-segregated with stem rust resistance in the two independent resistant lines, but its role in the resistance response is currently unclear. Conclusions: This study represents the first transcriptome analysis of responses to stem rust in wheat, and the first investigation of the resistance conferred by the newly-discovered wheat 7AL stem rust resistance locus. Microscopy showed the resistance response was associated with pre-haustorial cell death. Results of the RNA-seq, which has the resolution to discriminate between homeologous wheat genes, along with assignment of differentially expressed genes to wheat chromosomes, suggested putative receptor-like cytoplasmic kinases linked to the 7AL locus as candidate resistance genes for further investigation.
Project description:The assess the effect of AvrSr35 knock-out on host-pathogen interaction in the compatible host, we have performed time-course analysis of leaf transcriptomes obtained by infecting susceptible wheat cultivar Fielder with the wild type Puccinia graminis f.sp. tritici (Pgt) isolate 99KS76A-1 and its three mutants, M1, M4 and M7, that carry loss-of-function mutations in the AvrSr35 gene.