| Abstract Detail
Photomorphogenesis Gardner, Gary [1], Lin, Chentao [2], Tobin, Elaine M. [2], Loehrer, Heather [3], Brinkman, Doug [3]. The Effect of UV-B Irradiation on the Growth of Etiolated Arabidopsis Seedlings. Alteration of ‘normal’ levels of ultraviolet-B light (UV-B, 280-320 nm) can affect plant chemical composition, especially some phenolics, as well as growth. In recent years enormous progress has been made in describing fundamental aspects of plant photoreception. However, little is known about how plants perceive UV-B light. We seek to understand the effects of UV-B irradiation by 1) characterizing the growth inhibition of etiolated Arabidopsis seedlings by low fluence UV light; 2) characterizing the response in known mutants of photoreceptor genes and other genes involved in UV signal transduction and DNA repair; and 3) attempting to identify and characterize mutants of Arabidopsis that demonstrate a decreased sensitivity to UV-B. We have carried out fluence response curves, and, by the use of filtering plastics, demonstrated that the response is specific to UV-B light and not UV-A. The response shows reciprocity between duration and intensity, at least over a limited range. We are also in the process of determining an action spectrum, as well as response spectra, in the range 280-400 nm. This response occurs in mutant seedlings deficient in cryptochrome, phytochrome, or phototropin, suggesting that none of the known photoreceptors is the major UV-B photoreceptor. We have screened over 37,000 T-DNA insertion lines for reduced sensitivity to UV-B. Of these, 1555 were taller than the wild type under UV, 1332 of those were transplanted into soil, and 755 of those have produced seed to date. Thus far, we have carried out fluence-response experiments on 70 of those lines, and 8 of those 70 showed reduced sensitivity to UV-B. Characterization of these lines is in progress and will determine whether they are defective in the perception of UV-B.
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1 - University of Minnesota, Horticultural Science, 1970 Folwell Avenue, 305 Alderman Hall, St. Paul, MN, 55108, USA
2 - University of California, Los Angeles, Molecular, Cell and Developmental Biology
3 - University of Minnesota, Horticultural Science
Keywords:
UV-B
ultraviolet light
photomorphogenesis
Arabidopsis
growth inhibition
hypocotyl elongation.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P31004
Abstract ID:346 |
