UNIFOLIATA regulates leaf and flower morphogenesis in pea.
BACKGROUND
The vegetative phenotype of the pea mutant unifoliata (uni) is a simplification of the wild-type compound leaf to a single leaflet. Mutant uni plants are also self-sterile and the flowers resemble known floral meristem and organ identity mutants. In Antirrhinum and Arabidopsis, mutations in the floral meristem identity gene FLORICAULA/LEAFY (FLO/LFY) affect flower development alone, whereas the tobacco FLO/LFY homologue, NFL, is expressed in vegetative tissues, suggesting that NFL specifies determinacy in the progenitor cells for both flowers and leaves. In this paper, we characterised the pea homologue of FLO/LFY.


RESULTS
The pea cDNA homologue of FLO/LFY, PEAFLO, mapped to the uni locus in recombinant-inbred mapping populations and markers based on PEAFLO cosegregated with uni in segregating sibling populations. The characterisation of two spontaneous uni mutant alleles, one containing a deletion and the other a point mutation in the PEAFLO coding sequences, predicted that PEAFLO corresponds to UNI and that the mutant vegetative phenotype was conferred by the defective PEAFLO gene.


CONCLUSIONS
The uni mutant demonstrates that there are shared regulatory processes in the morphogenesis of leaves and flowers and that floral meristem identity genes have an extended role in plant development. Pleiotropic regulatory genes such as UNI support the hypothesis that leaves and flowers derive from a common ancestral sporophyll-like structure. The regulation of indeterminancy during leaf and flower morphogenesis by UNI may reflect a primitive function for the gene in the pre-angiosperm era.
Hofer
J
J
Department of Applied Genetics, John Innes Centre, Norwich, UK. hofer@bbarc.ac.uk
Turner
L
L
Hellens
R
R
Ambrose
M
M
Matthews
P
P
Michael
A
A
Ellis
N
N
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D010940:Plant Proteins