Functional & Integrative Genomics

, Volume 10, Issue 4, pp 619–627

Lipid transfer proteins and protease inhibitors as key factors in the priming of barley responses to Fusarium head blight disease by a biocontrol strain of Pseudomonas fluorescens

Authors

    • School of Biology and Environmental Science, Molecular Plant-Pathogen Interaction Group, Science WestUniversity College Dublin
  • Mojibur Khan
    • School of Biology and Environmental Science, Molecular Plant-Pathogen Interaction Group, Science WestUniversity College Dublin
  • Fiona Doohan
    • School of Biology and Environmental Science, Molecular Plant-Pathogen Interaction Group, Science WestUniversity College Dublin
Short Communication

DOI: 10.1007/s10142-010-0177-0

Cite this article as:
Petti, C., Khan, M. & Doohan, F. Funct Integr Genomics (2010) 10: 619. doi:10.1007/s10142-010-0177-0

Abstract

Strains of non-pathogenic pseudomonad bacteria, can elicit host defence responses against pathogenic microorganisms. Pseudomonas fluorescens strain MKB158 can protect cereals from pathogenesis by Fusarium fungi, including Fusarium head blight which is an economically important disease due to its association with both yield loss and mycotoxin contamination of grain. Using the 22 K barley Affymetrix chip, trancriptome studies were undertaken to determine the local effect of P. fluorescens strain MKB158 on the transcriptome of barley head tissue, and to discriminate transcripts primed by the bacterium to respond to challenge by Fusarium culmorum, a causal agent of the economically important Fusarium head blight disease of cereals. The bacterium significantly affected the accumulation of 1203 transcripts and primed 74 to positively, and 14 to negatively, respond to the pathogen (P = 0.05). This is the first study to give insights into bacterium priming in the Triticeae tribe of grasses and associated transcripts were classified into 13 functional classes, associated with diverse functions, including detoxification, cell wall biosynthesis and the amplification of host defence responses. In silico analysis of Arabidopsis homologs of bacterium-primed barley genes indicated that, as is the case in dicots, jasmonic acid plays a role in pseudomonad priming of host responses. Additionally, the transcriptome studies described herein also reveal new insights into bacterium-mediated priming of host defences against necrotrophs, including the positive effects on grain filling, lignin deposition, oxidative stress responses, and the inhibition of protease inhibitors and proteins that play a key role in programmed cell death.

Keywords

AquaporinsCell wallChymotrypsinGibberellinsInduced resistanceJasmonic acidnsLTPSerpinsSeed storage proteins

Supplementary material

10142_2010_177_MOESM1_ESM.doc (20 kb)
ESM 1(DOC 32 kb)
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Table S1Sequence of transcript-specific primers used for real time RT-PCR analyses. (DOC 49 kb)
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Table S2The effect of Pseudomonas fluorescens (strain MKB158), as compared to Fusarium culmorum (strain FCF200), on transcript accumulation in barley cultivar Lux head tissue at either 24 or 48 h post-pathogen treatment, as determined by microarray analysis. (DOC 18 kb)
10142_2010_177_MOESM4_ESM.doc (222 kb)
Table S3Description of the complementary potentiated transcripts not included in Table 1. Functional classification of barley (cultivar Lux) transcripts that were differentially regulated in head tissue in response to treatment with the biocontrol bacterium Pseudomonas fluorescens strain MKB158 and/or the pathogenic fungus Fusarium culmorum strain FCF200 at 24 or 48 h post-pathogen treatmenta. (DOC 221 kb)
10142_2010_177_MOESM5_ESM.doc (55 kb)
Fig. S1Venn diagrams highlighting the influence of the treatment with the bacterium Pseudomonas fluorescens (strain MKB158) on transcript accumulation in flowering heads of barley cultivar Lux in the absence and presence of the pathogen Fusarium culmorum (strain FCF200), as determined by microarray analysis. Diagrams represent the numbers of contigs (A) up-regulated and (B) down-regulated at 24 and/or 48 h post-pathogen treatment (pathogen was applied 24 h post-bacterium treatment). Numbers indicate the amount of barley contigs with significantly altered expression (P = 0.05) that are either shared or exclusive to bacterium or pathogen treatment. Codes: B, bacterium (P. fluorescens); P, pathogen (F. culmorum). (DOC 55 kb)
10142_2010_177_MOESM6_ESM.xls (818 kb)
Supplemental Expression Data FileExpression values (signals) detected for select probes of interesta on the barley affymetrix chip in barley head tissue in response to treatment with bacterium Pseudomonas fluorescens strain MKB158 (B), the fungal pathogen Fusarium culmorum strain FCF200 (P) or both agents in three experiments (Expt 1, Expt 2 and Expt 3) at either 24 or 48 h post-pathogen treatment. For each probe, detection signal and associated statistical significance (P values) are given. (XLS 817 kb)

Copyright information

© Springer-Verlag 2010