Down-regulation of the CrHPT1 histidine phosphotransfer protein prevents cytokinin-mediated up-regulation of CrDXR, and CrG10H transcript levels in periwinkle cell cultures
- 129 Downloads
In Catharanthus roseus cell cultures, cytokinins (CK) improve monoterpenoid indole alkaloids (MIAs) accumulation. This metabolite production is correlated with an increase of transcripts corresponding to genes encoding both elements of the CK-signaling pathway and enzymes implicated in MIAs biosynthesis. However, it has not been demonstrated that the CK signal, leading to MIAs accumulation, comes through components identified as belonging to the CK-signaling pathway. In this work, we addressed this question, by transgenesis, using an inducible RNAi system targeting element of CK-signaling. In transgenic lines, the up-regulation by CK of two genes involved in MIA biosynthesis was abolished. These results demonstrate a relationship between the CK-signaling and the MIAs biosynthetic pathways.
KeywordsCytokinin Catharanthus roseus Monoterpenoid indole alkaloids Gene regulation Inducible RNAi
This research was supported by the Ministère de l’Education Nationale et de la Technologie (MENRT, France). A doctoral grant was awarded by the MENRT to AA. Authors are grateful to N. H. Chua for providing the vector PTA-7001.
- 4.Argyros RD, Mathews DE, Chiang YH, Palmer CM, Thibault DM, Etheridge N, Argyros DA, Mason MG, Kieber JJ, Schaller GE (2009) Type B response regulators of Arabidopsis play key roles in cytokinin signaling and plant development. Plant Cell 20:2102–2116Google Scholar
- 7.Ginis O, Courdavault V, Melin C, Lanoue A, Giglioli-Guivarc’h N, St-Pierre B, Courtois M, Oudin A (2012) Molecular cloning and functional characterization of Catharanthus roseus hydroxymethylbutenyl 4-diphosphate synthase gene promoter from the methyl erythritol phosphate pathway. Mol Biol Rep. doi: 10.1007/s11033-011-1343-8 (in press)
- 11.Menke FL, Champion A, Kijne JW, Memelink J (1999) A novel jasmonate- and elicitor-responsive element in the periwinkle secondary metabolite biosynthetic gene Str interacts with a jasmonate- and elicitor-inducible AP2-domain transcription factor, ORCA2. EMBO J 18:4455–4463PubMedCrossRefGoogle Scholar
- 13.Papon N, Oudin A, Clastre M, Rideau M, Chénieux JC, Crèche J (2002) Isolation of CrHPT1, a cDNA encoding a histidine-containing phosphotransfer domain in Catharanthus roseus. Acta Bot Gallica 149:67–77Google Scholar
- 24.Yokoyama A, Yamashino T, Amano Y, Tajima Y, Imamura A, Sakakibara H, Mizuno T (2007) Type-B ARR transcription factors, ARR10 and ARR12, are implicated in cytokinin-mediated regulation of protoxylem differentiation in roots of Arabidopsis thaliana. Plant Cell Physiol 48:84–96PubMedCrossRefGoogle Scholar