Light-Stimulated Cotyledon Expansion in Arabidopsis Seedlings (The Role of Phytochrome B)
- 1 March 1994
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 104 (3), 1027-1032
- https://doi.org/10.1104/pp.104.3.1027
Abstract
Leaf and cotyledon expansion in dicotyledonous plants is a light-dependent developmental process. The unique role of phytochrome B has been tested by investigating expansion of cotyledons in wild-type and phytochrome-deficient mutants of Arabidopsis thaliana (L.) Heynh. A relatively rapid method for measuring cotyledon area was developed to quantify growth in large populations (average n [greater than or equal to] 100) of wild-type or mutant seedlings under different light and chemical treatments. Three-day-old wild-type (La-er) Arabidopsis seedlings, grown in saturating, low-fluence red light (2–4 [mu]mol m-2 s-1), showed a >250% increase in cotyledon area after 48 h of bright-red light when compared with the phytochrome mutants hy1, hy2, and hy3. An increase in epidermal cell area was observed in wild-type cotyledons but not in hy3, indicating that light-stimulated growth is due in part to cell expansion. The mutant phenotype was rescued by feeding the chromophore precursor biliverdin to the chromophore biosynthesis mutants hy1 and hy6. This treatment did not rescue the hy3 mutant. Since the hy3 lesion is specific to phytochrome B, we conclude that this pigment is involved in the enhancement of cotyledon cell expansion in bright-red light.Keywords
This publication has 16 references indexed in Scilit:
- Isolation and Initial Characterization of Arabidopsis Mutants That Are Deficient in Phytochrome APlant Physiology, 1993
- A New Class of Arabidopsis Constitutive Photomorphogenic Genes Involved in Regulating Cotyledon Development.Plant Cell, 1993
- Mutations in the gene for the red/far-red light receptor phytochrome B alter cell elongation and physiological responses throughout Arabidopsis development.Plant Cell, 1993
- COP9: a new genetic locus involved in light-regulated development and gene expression in arabidopsis.Plant Cell, 1992
- The hy3 Long Hypocotyl Mutant of Arabidopsis Is Deficient in Phytochrome B.Plant Cell, 1991
- Phytochrome-Deficient hy1 and hy2 Long Hypocotyl Mutants of Arabidopsis Are Defective in Phytochrome Chromophore Biosynthesis.Plant Cell, 1991
- Phenotypic and Genetic Analysis of det2, a New Mutant That Affects Light-Regulated Seedling Development in Arabidopsis.Plant Cell, 1991
- Different Roles for Phytochrome in Etiolated and Green Plants Deduced from Characterization of Arabidopsis thaliana Mutants.Plant Cell, 1989
- Mutants of Arabidopsis thaliana with altered phototropism.1989
- Biophysical Control of Plant Cell GrowthAnnual Review of Plant Physiology, 1986