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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-4-12
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1471-9053
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
621-34
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
gorgon, a novel missense mutation in the SHOOT MERISTEMLESS gene, impairs shoot meristem homeostasis in Arabidopsis.
pubmed:affiliation
Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192 Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't