title: CYCLIN-DEPENDENT KINASE8 differentially regulates plant immunity to fungal pathogens through kinase-dependent and -independent functions in Arabidopsis.
abstract: CYCLIN-DEPENDENT KINASE8 (CDK8) is a widely studied component of eukaryotic Mediator complexes. However, the biological and molecular functions of plant CDK8 are not well understood. Here, we provide evidence for regulatory functions of Arabidopsis thaliana CDK8 in defense and demonstrate its functional and molecular interactions with other Mediator and non-Mediator subunits. The cdk8 mutant exhibits enhanced resistance to Botrytis cinerea but susceptibility to Alternaria brassicicola. The contributions of CDK8 to the transcriptional activation of defensin gene PDF1.2 and its interaction with MEDIATOR COMPLEX SUBUNIT25 (MED25) implicate CDK8 in jasmonate-mediated defense. Moreover, CDK8 associates with the promoter of AGMATINE COUMAROYLTRANSFERASE to promote its transcription and regulate the biosynthesis of the defense-active secondary metabolites hydroxycinnamic acid amides. CDK8 also interacts with the transcription factor WAX INDUCER1, implying its additional role in cuticle development. In addition, overlapping functions of CDK8 with MED12 and MED13 and interactions between CDK8 and C-type cyclins suggest the conserved configuration of the plant Mediator kinase module. In summary, while CDK8's positive transcriptional regulation of target genes and its phosphorylation activities underpin its defense functions, the impaired defense responses in the mutant are masked by its altered cuticle, resulting in specific resistance to B. cinerea.
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Yingfang
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Schluttenhoffer
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Fuyou
authors.initials: F
authors.lastname: Fu
authors.affiliation: Bioinformatics Core, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Jyothi
authors.initials: J
authors.lastname: Thimmapuram
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Jian-Kang
authors.initials: JK
authors.lastname: Zhu
authors.affiliation: Division of Applied Life Sciences (BK21 Plus Program), Gyeongsang National University, Jinju City 660-701, Korea.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Applied Life Sciences (BK21 Plus Program), Gyeongsang National University, Jinju City 660-701, Korea.
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907 mengiste@purdue.edu.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Mengiste
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000528:Alternaria / Q000276:immunology / Q000502:physiology; D000577:Amides / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020171:Botrytis / Q000276:immunology / Q000502:physiology; D003373:Coumaric Acids / Q000378:metabolism; D056745:Cyclin C / Q000235:genetics / Q000378:metabolism; D056850:Cyclin-Dependent Kinase 8 / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D020869:Gene Expression Profiling; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics* / Q000276:immunology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation
chemical_list: D000217:Acyltransferases; D000577:Amides; D029681:Arabidopsis Proteins; D003373:Coumaric Acids; D056745:Cyclin C; D056850:Cyclin-Dependent Kinase 8; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C546592:CENTRAL CITY protein, Arabidopsis; C546591:GRAND CENTRAL protein, Arabidopsis; C121819:PDF1 protein, Arabidopsis; C475686:PFT1 protein, Arabidopsis; C474024:agmatine coumaroyltransferase; C522174:AT5G63610 protein, Arabidopsis