Functional dissection of the PROPEP2 and PROPEP3 promoters reveals the importance of WRKY factors in mediating microbe-associated molecular pattern-induced expression

• Published in: The New phytologist Vol. 198; no. 4; pp. 1165 - 1177
• Main Authors: Logemann, Elke, Birkenbihl, Rainer P., Rawat, Vimal, Schneeberger, Korbinian, Schmelzer, Elmon, Somssich, Imre E.
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.06.2013; Wiley Subscription Services, Inc
• Subjects: Arabidopsis - genetics; Arabidopsis - microbiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; as1/OCS (activation sequence‐1/octopine synthase) enhancer; Bacteria - metabolism; Base Pairing - genetics; Base Sequence; Boxes; Brassicaceae; Chromatin; chromatin immunoprecipitation; cis‐regulatory elements; Damage patterns; Deoxyribonucleic acid; DNA; DNA, Plant - genetics; Gene Expression Regulation, Plant; Genes; Genetic mutation; Genetic research; Immunoprecipitation; Kinases; Leaves; Leucine; Microorganisms; Molecular Sequence Data; Nucleotide sequence; Octopine; Oomycetes; Parsley; parsley protoplasts; Pathogens; Peptides; Petroselinum crispum; phastCons program; Phylogeny; Plants; Plants, Genetically Modified; Promoter regions; Promoter Regions, Genetic; Promoters; PROPEP 1; Protoplasts; Receptors; Receptors, Pattern Recognition - metabolism; Regions; Regulators; Sequence Deletion - genetics; Transcription; Transcription factors; Transcription Factors - metabolism; Transgenic plants; transient expression assay; W box
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12233

In Arabidopsis thaliana, small peptides (AtPeps) encoded by PROPEP genes act as damageassociated molecular patterns (DAMPs) that are perceived by two leucine-rich repeat receptor kinases, PEPR1 and PEPR2, to amplify defense responses. In particular, expression of PROPEP2 and PROPEP3 is strongly and rapidly induced by AtPeps, in response to bacterial, oomycete, and fungal pathogens, and microbe-associated molecular patterns (MAMPs). The cis-regulatory modules (CRMs) within the PROPEP2 and PROPEP3 promoters that mediate MAMP responsiveness were delineated, employing parsley (Petroselinum crispum) protoplasts and transgenic A. thaliana plants harboring promoter-reporter constructs. By chromatin immunoprecipitation in vivo, DNA interactions with a specific transcription factor were detected. Furthermore, the phastCons program was used to identify conserved regions of the PROPEP3 locus in different Brassicaceae species. The major MAMP-responsive CRM within the PROPEP2 promoter is composed of several W boxes and an as1/OCS (activation sequence-1/octopine synthase) enhancer element, while in the PROPEP3 promoter the CRM is comprised of six W boxes. The WRKY33 transcription factor binds in vivo to these promoter regions in a MAMP-dependent manner. Both the position and orientation of the six W boxes are conserved within the PROPEP3 promoters of four other Brassicaceae family members. WRKY factors are the major regulators of MAMP-induced PROPEP2 and PROPEP3 expression.