Identification of powdery mildew-induced barley genes by cDNA-AFLP: functional assessment of an early expressed MAP kinase

Eckey, Christina; Korell, Michael; Leib, Katja; Biedenkopf, Dagmar; Jansen, Carin; Langen, Gregor; Kogel, Karl‐Heinz

doi:10.1007/s11103-004-0275-2

Cited by 80 publications

(60 citation statements)

References 61 publications

(64 reference statements)

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“…Upon pathogen challenge and activation by a matching fungal avirulence protein, the MLA receptor is re-localized to the nucleus where it recruits WRKY1 and WRKY2 away from the promoters of defense genes. As expected, silencing of these WRKY transcription factors results in enhanced basal defense against Bgh (Shen et al, 2007, Eckey et al, 2004.…”

Section: Gene Switches: Transcription Factors and Gene Regulation Invsupporting

confidence: 78%

The Powdery Mildew Disease of Arabidopsis: A Paradigm for the Interaction between Plants and Biotrophic Fungi

Micali

Göllner

Humphry

et al. 2008

The Arabidopsis Book

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The powdery mildew diseases, caused by fungal species of the Erysiphales, have an important economic impact on a variety of plant species and have driven basic and applied research efforts in the field of phytopathology for many years. Although the first taxonomic reports on the Erysiphales date back to the 1850's, advances into the molecular biology of these fungal species have been hampered by their obligate biotrophic nature and difficulties associated with their cultivation and genetic manipulation in the laboratory. The discovery in the 1990's of a few species of powdery mildew fungi that cause disease on Arabidopsis has opened a new chapter in this research field. The great advantages of working with a model plant species have translated into remarkable progress in our understanding of these complex pathogens and their interaction with the plant host. Herein we summarize advances in the study of Arabidopsis-powdery mildew interactions and discuss their implications for the general field of plant pathology. We provide an overview of the life cycle of the pathogens on Arabidopsis and describe the structural and functional changes that occur during infection in the host and fungus in compatible and incompatible interactions, with special emphasis on defense signaling, resistance pathways, and compatibility factors. Finally, we discuss the future of powdery mildew research in anticipation of the sequencing of multiple powdery mildew genomes. The cumulative body of knowledge on powdery mildews of Arabidopsis provides a valuable tool for the study and understanding of disease associated with many other obligate biotrophic pathogen species.

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Section: Gene Switches: Transcription Factors and Gene Regulation Invsupporting

confidence: 78%

The Powdery Mildew Disease of Arabidopsis: A Paradigm for the Interaction between Plants and Biotrophic Fungi

Micali

Göllner

Humphry

et al. 2008

The Arabidopsis Book

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show abstract

“…They were found to act in a functionally redundant manner because elimination of individual W-boxes did not significantly reduce promoter activity. The two barley WRKY proteins WRKY1 and WRKY2 have been described as negative regulators of PTI as well as race-specific resistance (Eckey et al, 2004;Shen et al, 2007). By contrast, GER4 proteins have been found to enhance PTI in barley (Christensen et al, 2004;Zimmermann et al, 2006), which raises a question about negative regulation of GER4 promoters by WRKY1/2.…”

Section: Discussionmentioning

confidence: 99%

“…This response is also evolutionarily conserved and includes the formation of local cell wall appositions and the accumulation of pathogenesis-related proteins as well as antimicrobial small molecules termed phytoalexins (Hammerschmidt, 1999;Dixon, 2001). In cultivated barley (Hordeum vulgare ssp vulgare), PTI to the barley powdery mildew fungus Blumeria graminis f. sp hordei (Bgh) has been studied in terms of defense-related genes and proteins (Caldo et al, 2004;Eckey et al, 2004;Dong et al, 2006), cell wall appositions (Wei et al, 1998;Hü ckelhoven et al, 1999;An et al, 2006), and key regulatory factors, such as the Mlo gene (Kim et al, 2002;Opalski et al, 2005;Zierold et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Promoters of the Barley Germin-LikeGER4Gene Cluster Enable Strong Transgene Expression in Response to Pathogen Attack

et al. 2010

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Immunity of plants triggered by pathogen-associated molecular patterns (PAMPs) is based on the execution of an evolutionarily conserved defense response that includes the accumulation of pathogenesis-related (PR) proteins as well as multiple other defenses. The most abundant PR transcript of barley (Hordeum vulgare) leaf epidermis attacked by the powdery mildew fungus Blumeria graminis f. sp hordei encodes the germin-like protein GER4, which has superoxide dismutase activity and functions in PAMP-triggered immunity. Here, we show that barley GER4 is encoded by a dense cluster of tandemly duplicated genes (GER4a-h) that underwent several cycles of duplication. The genomic organization of the GER4 locus also provides evidence for repeated gene birth and death cycles. The GER4 promoters contain multiple WRKY factor binding sites (W-boxes) preferentially located in promoter fragments that were exchanged between subfamily members by gene conversion. Mutational analysis of TATA-box proximal W-boxes used GER4c promoter-b-glucuronidase fusions to reveal their enhancing effects and functional redundancy on pathogen-induced promoter activity. The data suggest enhanced transcript dosage as an evolutionary driving force for the local expansion and functional redundancy of the GER4 locus. In addition, the GER4c promoter provides a tool to study signal transduction of PAMP-triggered immunity and to engineer strictly localized and pathogen-regulated disease resistance in transgenic cereal crops.

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“…Recently, high-throughput transcriptome analyses have helped define the responses triggered in plant tissues upon recognition of these fungal pathogens. These studies were performed under conditions promoting activation of defenses involving either host resistance (Caldo et al, 2004;Eckey et al, 2004;Eulgem et al, 2004;Zierold et al, 2005;Michel et al, 2006) or nonhost resistance (Zimmerli et al, 2004;Bruggmann et al, 2005). Under conditions leading to compatibility, basic gene expression changes have been examined in Vicia faba (Wirsel et al, 2001), barley (Hordeum vulgare; Gjetting et al, 2004), and Brassica oleracea (Casimiro et al, 2006).…”

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confidence: 99%

Genome-Wide Expression Profiling Arabidopsis at the Stage ofGolovinomyces cichoracearumHaustorium Formation

et al. 2008

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(T.S., K.D.)Compatibility between plants and obligate biotrophic fungi requires fungal mechanisms for efficiently obtaining nutrients and counteracting plant defenses under conditions that are expected to induce changes in the host transcriptome. A key step in the proliferation of biotrophic fungi is haustorium differentiation. Here we analyzed global gene expression patterns in Arabidopsis thaliana leaves during the formation of haustoria by Golovinomyces cichoracearum. At this time, the endogenous levels of salicylic acid (SA) and jasmonic acid (JA) were found to be enhanced. The responses of wild-type, npr1-1, and jar1-1 plants were used to categorize the sensitivity of gene expression changes to NPR1 and JAR1, which are components of the SA and JA signaling pathways, respectively. We found that the infection process was the major source of variation, with 70 genes identified as having similarly altered expression patterns regardless of plant genotype. In addition, principal component analysis (PCA) identified genes responding both to infection and to lack of functional JAR1 (17 genes) or NPR1 (18 genes), indicating that the JA and SA signaling pathways function as secondary sources of variation. Participation of these genes in the SA or JA pathways had not been described previously. We found that some of these genes may be sensitive to the balance between the SA and JA pathways, representing novel markers for the elucidation of cross-talk points between these signaling cascades. Conserved putative regulatory motifs were found in the promoter regions of each subset of genes. Collectively, our results indicate that gene expression changes in response to infection by obligate biotrophic fungi may support fungal nutrition by promoting alterations in host metabolism. In addition, these studies provide novel markers for the characterization of defense pathways and susceptibility features under this infection condition.

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Identification of powdery mildew-induced barley genes by cDNA-AFLP: functional assessment of an early expressed MAP kinase

Cited by 80 publications

References 61 publications

The Powdery Mildew Disease of Arabidopsis: A Paradigm for the Interaction between Plants and Biotrophic Fungi

The Powdery Mildew Disease of Arabidopsis: A Paradigm for the Interaction between Plants and Biotrophic Fungi

Promoters of the Barley Germin-LikeGER4Gene Cluster Enable Strong Transgene Expression in Response to Pathogen Attack

Genome-Wide Expression Profiling Arabidopsis at the Stage ofGolovinomyces cichoracearumHaustorium Formation

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