Abstract
Addition of 6 μM indole-3-acetic acid (IAA) to incubation buffer increases the sensitivity of coleoptile sections cut from dark-grown Avena sativa L. cv. Lodi to red light by a factor of 10,000, relative to the response in the absence of added IAA, without changing the maximum amount of light-induced growth. From 0.03 to 4 μM IAA sections show at least a 100-fold increase in sensitivity to red light relative to the response in the absence of added IAA. In this IAA concentration range, the light-induced increase in elongation shows two phases of response to red-light fluence, which are separated by a plateau. The biphasic fluence-response curve is also characteristic of the red-light-induced stimulation of coleoptile growth in intact dark-grown seedlings. The effect of IAA on the sensitivity of the phytochrome-mediated growth response appears to be on some step in the transduction of the phytochrome signal, rather than on the growth response itself.
Keywords: auxin, photomorphogenesis, Avena, Zea, signal transduction
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bandurski R. S., Schulze A. Concentrations of Indole-3-acetic Acid and Its Esters in Avena and Zea. Plant Physiol. 1974 Sep;54(3):257–262. doi: 10.1104/pp.54.3.257. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hopkins W. G., Hillman W. S. Relationships between phytochrome state and photosensitive growth of Avena coleoptile segments. Plant Physiol. 1966 Apr;41(4):593–598. doi: 10.1104/pp.41.4.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Liverman J. L., Bonner J. The Interaction of Auxin and Light in the Growth Responses of Plants. Proc Natl Acad Sci U S A. 1953 Sep;39(9):905–916. doi: 10.1073/pnas.39.9.905. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mandoli D. F., Briggs W. R. Phytochrome control of two low-irradiance responses in etiolated oat seedlings. Plant Physiol. 1981 Apr;67(4):733–739. doi: 10.1104/pp.67.4.733. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schaer J. A., Mandoli D. F., Briggs W. R. Phytochrome-mediated cellular photomorphogenesis. Plant Physiol. 1983 Jul;72(3):706–712. doi: 10.1104/pp.72.3.706. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shinkle J. R., Briggs W. R. Auxin concentration/growth relationship for Avena coleoptile sections from seedlings grown in complete darkness. Plant Physiol. 1984 Feb;74(2):335–339. doi: 10.1104/pp.74.2.335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vanderhoef L. N., Briggs W. R. Red Light-inhibited Mesocotyl Elongation in Maize Seedlings: I. The Auxin Hypothesis. Plant Physiol. 1978 Apr;61(4):534–537. doi: 10.1104/pp.61.4.534. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vesper M. J., Evans M. L. Time-dependent Changes in the Auxin Sensitivity of Coleoptile Segments: Apparent Sensory Adaptation. Plant Physiol. 1978 Feb;61(2):204–208. doi: 10.1104/pp.61.2.204. [DOI] [PMC free article] [PubMed] [Google Scholar]