The bioassay to follow disease transition from 3 to 14 dai.

<p>(A) Fungal biomass expressed as content of <i>S. tritici</i> DNA. Significant increases (<i>P</i> < 0.05) in levels of fungal DNA are indicated by asterisks. (B) Wheat β-1,3-glucanase and chitinase gene expression analysed by qPCR. (C) β-1,3-glucanase and chitinase protein activities expressed as released glucose (μM) and OD₄₀₅ measurement based on the assays, respectively. Significant differences (<i>P</i> < 0.05) between infected and control samples are indicated by asterisks. (D) Chitinase protein expression in protein extracts from control (upper panel) and <i>S. tritici</i>-infected leaves (lower panel) analysed by western blotting. Bands indicate chitinase. Representatives of two biological replicates at each time point are shown for the control and infected plants.</p

Detection of hydrogen peroxide in <i>S. tritici</i>-infected wheat leaves from 3 to 14 dai.

<p>DAB was used for staining H₂O₂ (red-brown staining). Fungal surface structures were stained with Evans blue. Arrows indicate attempted fungal penetration through the stomata. </p

Expression patterns of selected <i>S. tritici</i> transcripts during infection.

Expression patterns of selected S. tritici transcripts during infection.</p

Principal component analysis of the transcriptome data.

<p>Principal components (PCs) 1, 2 and 3 account for 73.9, 11.6 and 7% of the variance, respectively. C₄, control at 4 dai; C₁₀, control at 10 dai; C₁₃, control at 13 dai; I₄, S. <i>tritici</i>-infected wheat at 4 dai; I₁₀, S. <i>tritici</i>-infected wheat at 10 dai; I₁₃, S. <i>tritici</i>-infected wheat at 13 dai.</p

Transcriptional Reprogramming of Wheat and the Hemibiotrophic Pathogen <i>Septoria tritici</i> during Two Phases of the Compatible Interaction

<div><p>The disease septoria leaf blotch of wheat, caused by fungal pathogen <i>Septoria tritici</i>, is of worldwide concern. The fungus exhibits a hemibiotrophic lifestyle, with a long symptomless, biotrophic phase followed by a sudden transition to necrotrophy associated with host necrosis. Little is known about the systematic interaction between fungal pathogenicity and host responses at specific growth stages and the factors triggering the transition. In order to gain some insights into global transcriptome alterations in both host and pathogen during the two phases of the compatible interaction, disease transition was monitored using pathogenesis-related gene markers and H₂O₂ signature prior to RNA-Seq. Transcriptome analysis revealed that the slow symptomless growth was accompanied by minor metabolic responses and slightly suppressed defences in the host, whereas necrotrophic growth was associated with enhanced host responses involving energy metabolism, transport, signalling, defence and oxidative stress as well as a decrease in photosynthesis. The fungus expresses distinct classes of stage-specific genes encoding potential effectors, probably first suppressing plant defence responses/facilitating the symptomless growth and later triggering life style transition and inducing host necrosis/facilitating the necrotrophic growth. Transport, signalling, anti-oxidative stress mechanisms and apoplastic nutrient acquisition play important roles in the entire infection process of <i>S. tritici</i>. Our findings uncover systematic <i>S. tritici</i>-induced expression profiles of wheat related to specific fungal infection strategies and provide a transcriptome resource for studying both hosts and pathogens in plant-Dothideomycete interactions. </p></div

Overview of sequencing transcriptome data from wheat leaves.

<p>Overview of sequencing transcriptome data from wheat leaves.</p

Functional category distribution in the ten expression clusters of fungal transcripts.

<p>The fungal transcripts were identified from <i>S. tritici</i>-infected wheat at 4, 10 and 13 dai. Expression level of the transcripts was calculated by log₂FPKM. Histogram representation of the category distribution is expressed as percentage of the amount of transcripts belonging to the cluster. Transcripts coding for unknown products were included in the analysis. The clusters fall into three groups (A, B and C) based on the major profiling over the time course.</p

Heat map visualization of differentially expressed wheat transcripts.

<p>The plant transcripts are mainly involved in primary metabolism, signalling, transport and stress and defence in response to <i>S. tritici</i>. Differential expression patterns are based on the log₂ fold changes of transcript abundance in <i>S. tritici</i>-infected wheat <i>versus</i> controls at 4, 10 and 13 dai.</p

Illustrated the partly distribution (ratio of alignment/short no less than 0.8) of homologous length and aligned length.

<p>The X axis represents the ratio is length of pepper EST/unigene length, the Y axis is represents the ratio of alignment length/shorter between pepper EST and unigene.</p

Comparison of <i>de novo</i> assembly using Trinity and Velvet-oases programs.

*<p>Represents the number of contigs that at less 200 bp in length.</p>#<p>represents the result of TIGCL and Phrap for reduce the redundancy after Trinity with 25-mer assembly.</p