The delayed terminal flower phenotype is caused by a conditional mutation in the CENTRORADIALIS gene of snapdragon.
The snapdragon (Antirrhinum majus) centroradialis mutant (cen) is characterized by the development of a terminal flower, thereby replacing the normally open inflorescence by a closed inflorescence. In contrast to its Arabidopsis counterpart, terminal flower1, the cen-null mutant displays an almost constant number of lateral flowers below the terminal flower. Some partial revertants of an X-radiation-induced cen mutant showed a delayed formation of the terminal flower, resulting in a variable number of lateral flowers. The number of lateral flowers formed was shown to be environmentally controlled, with the fewer flowers formed under the stronger flower-inducing conditions. Plants displaying this "Delayed terminal flower" phenotype were found to be heterozygous for a mutant allele carrying a transposon in the coding region and an allele from which the transposon excised, leaving behind a 3-bp duplication as footprint. As a consequence, an iso-leucine is inserted between Asp148 and Gly149 in the CENTRORADIALIS protein. It is proposed that this mutation results in a low level of functional CEN activity, generating a phenotype that is more similar to the Arabidopsis Terminal flower phenotype.
Cremer
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Max-Planck Institut für Züchtungsforschung, Carl-von-Linné Weg 10, 50829 Köln, Germany. cremer@mpiz-koeln.mpg.de
Lönnig
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WE
Saedler
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H
Huijser
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P
D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D004251:DNA Transposable Elements; D018744:DNA, Plant; D017343:Genes, Plant; D019684:Magnoliopsida / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D018514:Plant Structures / Q000033:anatomy & histology; D011487:Protein Conformation
C098219:CEN protein, Antirrhinum majus; D004251:DNA Transposable Elements; D018744:DNA, Plant; D010940:Plant Proteins