| Abstract Detail
Photosynthesis(Light) Goins, Gregory [1], Smith, Mary [2]. Molecular analysis of photosynthetic acclimation to altered spectral quality. Photosynthetic acclimation enables a plant to balance between the needs to efficiently capture limiting light or to avoid potentially damaging effects of excess irradiance. Long-term photosynthetic acclimation entails changed gene expression invoking molecular re-arrangements in the chloroplast. Plants have multiple light-sensing (photoreceptors) and redox-sensing systems for the perception of the level and quality of light. The sensing mechanism(s) for changing light conditions and subsequent signal transduction are poorly understood. There is current debate as to whether adjustments in the photosynthetic apparatus are largely regulated by reduction-oxidation (redox) status of the photosynthetic electron transport chain or activation of the photoreceptors. Our work was accomplished by direct comparison of the effects from two different techniques (biased photosynthetic photosystem excitation and electron transport inhibition) to alter redox status of the plastoquinone pool in wild-type and photoreceptor mutant Arabidopsis. With specific electron transport inhibitors, we modulated redox status of the plastoquinone pool (PQ-pool) to determine if the same gene expression patterns are observed as compared to plants transferred to altered spectral qualities (660 nm [PSII] or 700 nm [PSI] light) without inhibitors. The concentrations of photosynthetic electron transport inhibitors used only gave partial inhibition of oxygen evolution, thereby minimizing side effect on chloroplast metabolism. A major strength of the experimental design was that it allows us to distinguish between physiological processes, as well as between genes that are regulated by spectral quality, which we hypothesize reflects alterations in photosynthetic apparatus redox state. Recent data established if there is a link between acclimation to spectral quality and gene expression under the control of the redox state of the PQ-pool of the thylakoid membranes.
Log in to add this item to your schedule
1 - North Carolina A&T State University, Biology, 1601 E. Market Street, 104 Barnes Hall, Greensboro, NC, 27411, USA
2 - North Carolina A&T State University, Biology, 1601 E. Market Street, 104 Barnes Hall, Greensboro, NC, 27411, USA
Keywords:
Photosynthesis
light
spectral quality
redox
plastiquinone
photoreceptor.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P12005
Abstract ID:806 |
