title: A differentially regulated AP2/ERF transcription factor gene cluster acts downstream of a MAP kinase cascade to modulate terpenoid indole alkaloid biosynthesis in Catharanthus roseus.
abstract: Catharanthus roseus produces bioactive terpenoid indole alkaloids (TIAs), including the chemotherapeutics, vincristine and vinblastine. Transcriptional regulation of TIA biosynthesis is not fully understood. The jasmonic acid (JA)-responsive AP2/ERF transcription factor (TF), ORCA3, and its regulator, CrMYC2, play key roles in TIA biosynthesis. ORCA3 forms a physical cluster with two uncharacterized AP2/ERFs, ORCA4 and 5. Here, we report that (1) the ORCA gene cluster is differentially regulated; (2) ORCA4, while overlapping functionally with ORCA3, modulates an additional set of TIA genes. Unlike ORCA3, ORCA4 overexpression resulted in dramatic increase of TIA accumulation in C. roseus hairy roots. In addition, CrMYC2 is capable of activating ORCA3 and co-regulating TIA pathway genes concomitantly with ORCA3. The ORCA gene cluster and CrMYC2 act downstream of a MAP kinase cascade that includes a previously uncharacterized MAP kinase kinase, CrMAPKK1. Overexpression of CrMAPKK1 in C. roseus hairy roots upregulated TIA pathways genes and increased TIA accumulation. This work provides detailed characterization of a TF gene cluster and advances our understanding of the transcriptional and post-translational regulatory mechanisms that govern TIA biosynthesis in C. roseus.
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Priyanka
authors: P
authors: Paul
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Sanjay K
authors: SK
authors: Singh
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Barunava
authors: B
authors: Patra
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Xueyi
authors: X
authors: Sui
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Sitakanta
authors: S
authors: Pattanaik
authors: Department of Plant and Soil Sciences and Kentucky Tobacco Research Development Center, University of Kentucky, 1401 University Drive, Lexington, KY, 40546, USA.
authors: Ling
authors: L
authors: Yuan
mesh_terms: D000085:Acetates / Q000494:pharmacology; D020816:Amino Acid Motifs; D030008:Catharanthus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics*; D055442:Metabolome / Q000235:genetics; D008954:Models, Biological; D005810:Multigene Family; D054883:Oxylipins / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D059828:Plant Cells / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D046948:Secologanin Tryptamine Alkaloids; D014157:Transcription Factors; C072239:methyl jasmonate
keywords: AP2/ERF gene cluster; Catharanthus roseus (Madagascar periwinkle); MAP kinase; phosphorylation; terpenoid indole alkaloids (TIAs); transcriptional regulation