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IAA8 involved in lateral root formation interacts with the TIR1 auxin receptor and ARF transcription factors in Arabidopsis.
- Source :
-
PloS one [PLoS One] 2012; Vol. 7 (8), pp. e43414. Date of Electronic Publication: 2012 Aug 17. - Publication Year :
- 2012
-
Abstract
- The expression of auxin-responsive genes is regulated by the TIR1/AFB auxin receptor-dependent degradation of Aux/IAA transcriptional repressors, which interact with auxin-responsive factors (ARFs). Most of the 29 Aux/IAA genes present in Arabidopsis have not been functionally characterized to date. IAA8 appears to have a distinct function from the other Aux/IAA genes, due to its unique transcriptional response to auxin and the stability of its encoded protein. In this study, we characterized the function of Arabidopsis IAA8 in various developmental processes governed by auxin and in the transcriptional regulation of the auxin response. Transgenic plants expressing estrogen-inducible IAA8 (XVE::IAA8) exhibited significantly fewer lateral roots than the wild type, and an IAA8 loss-of-function mutant exhibited significantly more. Ectopic overexpression of IAA8 resulted in abnormal gravitropism. The strong induction of early auxin-responsive marker genes by auxin treatment was delayed by IAA8 overexpression. GFP-fusion analysis revealed that IAA8 localized not only to the nucleus, but, in contrast to other Aux/IAAs, also to the cytosol. Furthermore, we demonstrated that IAA8 interacts with TIR1, in an auxin-dependent fashion, and with ARF proteins, both in yeast and in planta. Taken together, our results show that IAA8 is involved in lateral root formation, and that this process is regulated through the interaction with the TIR1 auxin receptor and ARF transcription factors in the nucleus.
- Subjects :
- Arabidopsis growth & development
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Cell Nucleus metabolism
Cytosol metabolism
DNA-Binding Proteins metabolism
F-Box Proteins metabolism
Gene Expression Regulation, Developmental drug effects
Gene Expression Regulation, Plant drug effects
Indoleacetic Acids pharmacology
Luminescent Proteins genetics
Luminescent Proteins metabolism
Microscopy, Confocal
Mutation
Plant Growth Regulators pharmacology
Plant Roots growth & development
Plant Roots metabolism
Plants, Genetically Modified
Protein Binding drug effects
Protoplasts cytology
Protoplasts metabolism
Receptors, Cell Surface metabolism
Reverse Transcriptase Polymerase Chain Reaction
Transcription Factors metabolism
Two-Hybrid System Techniques
Arabidopsis genetics
Arabidopsis Proteins genetics
DNA-Binding Proteins genetics
F-Box Proteins genetics
Plant Roots genetics
Receptors, Cell Surface genetics
Transcription Factors genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 7
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 22912871
- Full Text :
- https://doi.org/10.1371/journal.pone.0043414