A conserved microRNA module exerts homeotic control over Petunia hybrida and Antirrhinum majus floral organ identity.
It is commonly thought that deep phylogenetic conservation of plant microRNAs (miRNAs) and their targets indicates conserved regulatory functions. We show that the blind (bl) mutant of Petunia hybrida and the fistulata (fis) mutant of Antirrhinum majus, which have similar homeotic phenotypes, are recessive alleles of two homologous miRNA-encoding genes. The BL and FIS genes control the spatial restriction of homeotic class C genes to the inner floral whorls, but their ubiquitous early floral expression patterns are in contradiction with a potential role in patterning C gene expression. We provide genetic evidence for the unexpected function of the MIRFIS and MIRBL genes in the center of the flower and propose a dynamic mechanism underlying their regulatory role. Notably, Arabidopsis thaliana, a more distantly related species, also contains this miRNA module but does not seem to use it to confine early C gene expression to the center of the flower.
Cartolano
Maria
M
Max Planck Institut für Züchtungsforschung, Plant Molecular Genetics Department, Carl-von-Linne-Weg 10, 50829 Köln, Germany.
Castillo
Rosa
R
Efremova
Nadia
N
Kuckenberg
Markus
M
Zethof
Jan
J
Gerats
Tom
T
Schwarz-Sommer
Zsuzsanna
Z
Vandenbussche
Michiel
M
D032161:Antirrhinum / Q000737:chemistry / Q000235:genetics*; D019521:Body Patterning / Q000502:physiology; D017124:Conserved Sequence; D035264:Flowers / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D005801:Genes, Homeobox / Q000502:physiology*; D035683:MicroRNAs / Q000737:chemistry / Q000502:physiology*; D008969:Molecular Sequence Data; D032306:Petunia / Q000737:chemistry / Q000235:genetics*
D035683:MicroRNAs