KLUH/CYP78A5-dependent growth signaling coordinates floral organ growth in Arabidopsis.
Growth control in animals and plants involves mobile signals. Depending on their range of action, these signals coordinate the growth of cells within an organ or the growth of different organs in a larger, functionally integrated structure. In plants, flowers are such integrated structures, yet it remains poorly understood how growth of the constituent organs is coordinated to ensure their correct relative sizes. The cytochrome P450 KLUH/CYP78A5 and its homolog CYP78A7 promote organ growth via a non-cell-autonomous signal; however, the range of this signal and thus its developmental function are unknown. Here we use a system for the predictable generation of chimeric plants to determine the range of the KLUH-dependent signal. In contrast with the largely autonomous behavior of another tested growth-control gene, we find that KLUH activity extends beyond individual organs and flowers. Its overall activity is integrated across an inflorescence to determine final organ size, which is largely independent of the genotype of the individual organs. Thus, the KLUH-dependent signal appears to move beyond individual organs in a flower, providing a mechanism for coordinating their growth and ensuring floral symmetry as an important determinant of a plant's attractiveness to pollinators.
Eriksson
Sven
S
Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich NR47UH, UK.
Stransfeld
Lena
L
Adamski
Nikolai Maria
NM
Breuninger
Holger
H
Lenhard
Michael
M
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009154:Mutation; D009929:Organ Size / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D017931:DNA Primers; D018744:DNA, Plant; D003577:Cytochrome P-450 Enzyme System; C546334:KLUH protein, Arabidopsis