Flower colour intensity depends on specialized cell shape controlled by a Myb-related transcription factor

• Published in: Nature (London) Vol. 369; no. 6482; pp. 661 - 664
• Main Authors: Noda, Ken-ichi, Glover, Beverley J, Linstead, Paul, Martin, Cathie
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 23.06.1994; Nature Publishing Group
• Subjects: Amino Acid Sequence; Antirrhinum majus; Base Sequence; Biological and medical sciences; Cell biochemistry; Cell physiology; Color; Crosses, Genetic; DNA, Complementary; Flowers & plants; Fundamental and applied biological sciences. Psychology; Genes; Genes, Plant; Microscopy, Electron, Scanning; Molecular Sequence Data; Mutation; Pigmentation; Pigmentation - genetics; Pigmentation - physiology; Plant physiology and development; Plant Proteins - genetics; Plants - genetics; Plants - ultrastructure; Proteins; Proto-Oncogene Proteins - classification; Proto-Oncogene Proteins c-myb; Transcription Factors - classification; Transcription Factors - genetics; Transcription Factors - physiology; Flower; Nucleotide sequence; Antirrhinum majus; Color; Proteins; Characterization; Gene; Dicotyledones; Morphology; Angiospermae; Scrophulariaceae; Pigments; Flower crop; Spermatophyta; Light absorption; Mutation; Transcription factor; Cell; Aminoacid sequence
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/369661a0

Flower colour is determined primarily by the production of pigments, usually anthocyanins or carotenoids, but the shade and intensity of the colour are often changed by other factors such as vacuolar compounds, pH and metal ions. Pigmentation can also be affected by the shape of epidermal cells, especially those facing prospective pollinators. A conical shape is believed to increase the proportion of incident light that enters the epidermal cells, enhancing light absorption by the floral pigments, and thus the intensity of their colour. We have identified a gene (mixta) that affects the intensity of pigmentation of epidermal cells in Antirrhinum majus petals. The cells of the corolla lobes fail to differentiate into their normal conical form in mixta mutants. We have cloned the mixta gene by transposon tagging; its sequence reveals that it encodes a Myb-related protein that probably participates in the transcriptional control of epidermal cell shape.