Induction of Somatic Embryos in Arabidopsis Requires Local YUCCA Expression Mediated by the Down-Regulation of Ethylene Biosynthesis
- 1 July 2013
- journal article
- Published by Elsevier BV in Molecular Plant
- Vol. 6 (4), 1247-1260
- https://doi.org/10.1093/mp/sss154
Abstract
Somatic embryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results in somatic embryogenesis, the mechanisms underlying the initiation of somatic embryos (SEs) are poorly understood. In this study, we showed that YUCCAs (YUCs) encoding key enzymes in auxin biosynthesis are required for SE induction in Arabidopsis. To identify other factors mediating SE initiation, we performed transcriptional profiling and gene expression analysis. The results showed that genes involved in ethylene biosynthesis and its responses were down-regulated during SE initiation. Ethylene level decreased progressively during SE initiation, whereas treatment with the metabolic precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), or mutation of ETHYLENE-OVERPRODUCTION1 (ETO1) disrupted SE induction, suggesting that ethylene plays a role in this process. Suppression of SE induction was also observed in the constitutive triple response 1 (ctr1) mutant, in which ethylene signaling was enhanced. These results indicate that down-regulation of not only ethylene biosynthesis, but also ethylene response is critical for SE induction. We further showed that ethylene disturbed SE initiation through inhibiting YUC expression that might be involved in local auxin biosynthesis and subsequent auxin distribution. Our results provide new information on the mechanisms of hormone-regulated SE initiation.Keywords
This publication has 72 references indexed in Scilit:
- CTR1 phosphorylates the central regulator EIN2 to control ethylene hormone signaling from the ER membrane to the nucleus in ArabidopsisProceedings of the National Academy of Sciences, 2012
- Auxin and ethylene: collaborators or competitors?Trends in Plant Science, 2012
- Auxin–Cytokinin Interaction Regulates Meristem DevelopmentMolecular Plant, 2011
- Slicing across Kingdoms: Regeneration in Plants and AnimalsCell, 2008
- The Transcription Factor MtSERF1 of the ERF Subfamily Identified by Transcriptional Profiling Is Required for Somatic Embryogenesis Induced by Auxin Plus Cytokinin in Medicago truncatulaPlant Physiology, 2008
- Auxin biosynthesis by the YUCCA flavin monooxygenases controls the formation of floral organs and vascular tissues in ArabidopsisGenes & Development, 2006
- Gene Expression Programs during Shoot, Root, and Callus Development in Arabidopsis Tissue CulturePlant Physiology, 2006
- Convergence of Signaling Pathways in the Control of Differential Cell Growth in ArabidopsisDevelopmental Cell, 2004
- Regulation of ethylene gas biosynthesis by the Arabidopsis ETO1 proteinNature, 2004
- CTR1, a negative regulator of the ethylene response pathway in arabidopsis, encodes a member of the Raf family of protein kinasesCell, 1993