The mlo resistance alleles to powdery mildew infection in barley trigger a developmentally controlled defence mimic phenotype

Wolter, Marietta; Hollricher, Karin; Salamini, F.; Schulze‐Lefert, Paul

doi:10.1007/bf00281610

Cited by 300 publications

(183 citation statements)

References 19 publications

Supporting

Mentioning

171

Contrasting

Unclassified

Order By: Relevance

“…These mutants are thought to result from defects in genes that are responsible for the cell death phenotype linked with a hypersensitive reaction (HR) or resistance. Mutants which exhibit spontaneous lesions in the absence of pathogen infections are rather common and have for example been identified in maize (Hoisington et al 1982), barley (Wolter et al 1993, Rostoks et al 2003, rice (Yin et al 2000) and Arabidopsis thaliana (Lorrain et al 2003).…”

Section: Resultsmentioning

confidence: 99%

Barley mutants with enhanced level of resistance to Swedish isolates of Bipolaris sorokiniana, casual agent of spot blotch

Persson¹,

Rasmussen²,

Falk³

et al. 2008

Plant Breeding

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Barley mutants with enhanced level of resistance to Swedish isolates of Bipolaris sorokiniana, casual agent of spot blotch

Persson¹,

Rasmussen²,

Falk³

et al. 2008

Plant Breeding

View full text Add to dashboard Cite

show abstract

“…Lesions were observed on leaves of OsWRKY6-ox lines. Lesionmimic phenotypes are often related to pathogen defense responses and have been observed in plants such as barley (Hordeum vulgare), Arabidopsis, maize (Zea mays), and rice (Wolter et al, 1993;Dietrich et al, 1994;Johal et al, 1995;Takahashi et al, 1999). Generally, lesion-mimic mutants had constitutively activated defense responses including callose deposition, PR gene induction, and production and accumulation of ROS and phytoalexins (Staskawicz et al, 1995).…”

Section: New Phytologistmentioning

confidence: 99%

Molecular characterization of Oryza sativa WRKY6, which binds to W‐box‐like element 1 of the Oryza sativa pathogenesis‐related (PR) 10a promoter and confers reduced susceptibility to pathogens

et al. 2015

View full text Add to dashboard Cite

SummaryWRKY proteins are transcription factors (TFs) that regulate the expression of defenserelated genes. The salicylic acid (SA)-inducible Oryza sativa WRKY6 (OsWRKY6) was identified as a positive regulator of Oryza sativa pathogenesis-related 10a (OsPR10a) by transient expression assays. A physical interaction between OsWRKY6 and W-box-like element 1 (WLE1), which positively regulates OsPR10a/probenazole induced protein 1 expression, was verified in vitro.Several pathogenesis-related (PR) genes were constitutively activated, including OsPR10a, and transgenic rice (Oryza sativa) plants overexpressing (ox) OsWRKY6 exhibited enhanced disease resistance to pathogens. By contrast, PR gene induction was compromised in transgenic OsWRKY6-RNAi lines, suggesting that OsWRKY6 is a positive regulator of defense responses. OsWRKY6-ox lines displayed leaf lesions, and increased OsWRKY6 levels caused cell death.Salicylic acid (SA) concentrations were higher in OsWRKY6-ox lines than in wild-type (WT) plants, and transcript levels of Oryza sativa isochorismate synthase 1 (OsICS1), which encodes a major enzyme involved in SA biosynthesis, were higher in OsWRKY6-ox lines than in WT. OsWRKY6 directly bound to the OsICS1 promoter in vivo. This indicates that OsWRKY6 can directly regulate OsICS1 expression and thereby increase SA concentrations. OsWRKY6 autoregulates its own expression. OsWRKY6 protein degradation is possibly regulated by ubiquitination.Our results suggest that OsWRKY6 positively regulates defense responses through activation of OsICS1 expression and OsWRKY6 stabilization.

show abstract

“…Nevertheless, the use of plants carrying mlo alleles is associated with certain limitations. First, in the absence of pathogens, barley mlo plants spontaneously form callose-containing cell wall appositions (papillae), predominantly in the short cell type of the leaf epidermis (Wolter et al, 1993). Additionally, leaf mesophyll cells in mlo mutants undergo spontaneous cell death (Peterh€ ansel et al, 1997), which has been recognized as an indication of accelerated leaf senescence (Piffanelli et al, 2002).…”

mentioning

confidence: 99%

Magical mystery tour: MLO proteins in plant immunity and beyond

2014

View full text Add to dashboard Cite

Summary Stable heritable restriction of the ubiquitous powdery mildew disease is a desirable trait for agri‐ and horticulture. In barley (Hordeum vulgare), loss‐of‐function mutant alleles of the Mildew resistance locus o (Mlo) gene confer broad‐spectrum resistance to almost all known isolates of the fungal barley powdery mildew pathogen, Blumeria graminis f.sp. hordei. Despite extensive cultivation of barley mlo genotypes, mlo resistance has been durable in the field. Mlo genes are present as small families in the genomes of all higher plant species. The presumed negative regulatory role of particular members in plant immunity is evolutionarily conserved, as powdery mildew resistant mlo mutants have also been described in Arabidopsis thaliana, tomato (Solanum lycopersicum) and pea (Pisum sativum). Barley Mlo encodes a plasma membrane‐localized seven‐transmembrane domain protein of unknown biochemical activity. Here, we review the known requirements for mlo‐mediated disease resistance in barley and Arabidopsis and reflect current views regarding Mlo function. We discuss additional mlo mutant phenotypes recently discovered in Arabidopsis and present a meta‐analysis of the phylogenetic relationships within the Mlo family. Finally, we consider the novel versatile tools for functional analysis and targeted genome modification that can be used to induce mlo‐based powdery mildew resistance in virtually any plant species.

show abstract

The mlo resistance alleles to powdery mildew infection in barley trigger a developmentally controlled defence mimic phenotype

Cited by 300 publications

References 19 publications

Barley mutants with enhanced level of resistance to Swedish isolates of Bipolaris sorokiniana, casual agent of spot blotch

Barley mutants with enhanced level of resistance to Swedish isolates of Bipolaris sorokiniana, casual agent of spot blotch

Molecular characterization of Oryza sativa WRKY6, which binds to W‐box‐like element 1 of the Oryza sativa pathogenesis‐related (PR) 10a promoter and confers reduced susceptibility to pathogens

Magical mystery tour: MLO proteins in plant immunity and beyond

Contact Info

Product

Resources

About