title: Use of enhancer trapping to identify pathogen-induced regulatory events spatially restricted to plant-microbe interaction sites.
abstract: Plant genes differentially expressed during plant-pathogen interactions can be important for host immunity or can contribute to pathogen virulence. Large-scale transcript profiling studies, such as microarray- or mRNA-seq-based analyses, have revealed hundreds of genes that are differentially expressed during plant-pathogen interactions. However, transcriptional responses limited to a small number of cells at infection sites can be difficult to detect using these approaches, as they are under-represented in the whole-tissue datasets typically generated by such methods. This study examines the interactions between Arabidopsis thaliana (Arabidopsis) and the pathogenic oomycete Hyaloperonospora arabidopsidis (Hpa) by enhancer trapping to uncover novel plant genes involved in local infection responses. We screened a β-glucuronidase (GUS) reporter-based enhancer-trap population for expression patterns related to Hpa infection. Several independent lines exhibited GUS expression in leaf mesophyll cells surrounding Hpa structures, indicating a regulatory response to pathogen infection. One of these lines contained a single enhancer-trap insertion in an exon of At1g08800 (MyoB1, Myosin Binding Protein 1) and was subsequently found to exhibit reduced susceptibility to Hpa. Two additional Arabidopsis lines with T-DNA insertions in exons of MyoB1 also exhibited approximately 30% fewer spores than wild-type plants. This study demonstrates that our enhancer-trapping strategy can result in the identification of functionally relevant pathogen-responsive genes. Our results further suggest that MyoB1 either positively contributes to Hpa virulence or negatively affects host immunity against this pathogen.
authors.affiliation: ChemGen, Integrative Graduate Education and Research Traineeship Program, University of California, Riverside, CA, 92521, USA.|Institute for Integrative Genome Biology, Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Schroeder
authors.affiliation: Institute for Integrative Genome Biology, Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.
authors.forename: Tokuji
authors.initials: T
authors.lastname: Tsuchiya
authors.affiliation: College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
authors.forename: Shuilin
authors.initials: S
authors.lastname: He
authors.affiliation: Institute for Integrative Genome Biology, Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Eulgem
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D054884:Host-Pathogen Interactions / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009868:Oomycetes / Q000472:pathogenicity*; D060888:Real-Time Polymerase Chain Reaction; D013170:Spores / Q000502:physiology; D014774:Virulence
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; C036483:T-DNA
keywords: Arabidopsis thaliana; Hyaloperonospora arabidopsidis; MyoB1; compatibility factor; disease susceptibility; plant defence system; plant innate immunity