Back to Search
Start Over
gorgon, a Novel Missense Mutation in the SHOOT MERISTEMLESS Gene, Impairs Shoot Meristem Homeostasis in Arabidopsis
- Source :
- Plant and Cell Physiology. 51:621-634
- Publication Year :
- 2010
- Publisher :
- Oxford University Press (OUP), 2010.
-
Abstract
- The shoot meristem is a group of self-perpetuating cells that ultimately gives rise to the aerial parts of plants. The Arabidopsis thaliana SHOOT MERISTEMLESS (STM) gene, which encodes a knotted1-like homeobox transcription factor, is required for shoot meristem formation and maintenance, and loss-of-function mutations in the gene result in complete loss or premature termination of the shoot meristem. Here, we report a novel missense allele of STM, gorgon (gor), which displays striking differences in shoot meristem defects compared with known stm alleles. The gor phenotype results from substitution of the highly conserved arginine at position 53 of the homeodomain, which is important for DNA binding in other homeodomain proteins. In gor, the shoot meristem enlarges continuously during post-embryonic development and the floral meristems frequently develop additional whorls. These phenotypes, together with enlarged expression domains of meristem markers, indicate that the mutation affects shoot meristem activity in the opposite direction to other loss-of-function alleles. However, detailed genetic analyses and overexpression studies indicate that gor represents a novel type of hypomorphic alleles rather than the hypermorph that is suggested by the phenotype. Consistently, the gor allele strictly requires the functional PENNYWISE (PNY) gene, which encodes a known binding partner of the STM protein, to maintain shoot meristem activity, whereas the wild-type allele efficiently maintains the meristem even in the absence of PNY. Our results suggest a critical role for Arg53 of the homeodomain in STM function and that the gor mutation at this residue impairs shoot meristem homeostasis.
- Subjects :
- Physiology
Meristem
Arabidopsis
Mutation, Missense
Plant Science
Gene Expression Regulation, Plant
Two-Hybrid System Techniques
Missense mutation
Allele
Gene
In Situ Hybridization
Homeodomain Proteins
Regulation of gene expression
Genetics
biology
Arabidopsis Proteins
Reverse Transcriptase Polymerase Chain Reaction
fungi
food and beverages
Cell Biology
General Medicine
biology.organism_classification
ABC model of flower development
Microscopy, Electron, Scanning
Homeobox
Plant Shoots
Subjects
Details
- ISSN :
- 14719053 and 00320781
- Volume :
- 51
- Database :
- OpenAIRE
- Journal :
- Plant and Cell Physiology
- Accession number :
- edsair.doi.dedup.....a34a61f2614d579c6f201764c2815d8c