| Abstract Detail
Secondary Metabolism Buer, Charles S [1], Muday, Gloria K [2], Djordjevic, Michael A [3]. Flavonoids are differentially taken up, converted to downstream products, and transported long distances in the Arabidopsis tt4 mutants. Flavonoid compounds have a wide range of functions in plants and are synthesised in response to developmental and environmental signals. We asked whether the localization of these compounds was restricted to the site of synthesis using fluorescence microscopy in the presence of a stain that selectively interacts with flavonoids. The local application of aglycones to the tt4 flavonoid-less mutants of Arabidopsis thaliana resulted in fluorescence in tissues distal to the application site. This flavonoid accumulation was confirmed by HPLC, indicating flavonoid uptake and movement systems. Root tip applications of flavonoids resulted in basipetal movement, mainly in epidermal layers, at rates approaching 1 cm hr−1. The apparent acropetal rates of movement were about half that observed for root tip applications. Naringenin, dihydrokaempferol, and dihydroquercetin were taken up at all application sites: the root tip, mid-root, and cotyledons, and resulted in the long distance movement to distal tissues followed by conversion to quercetin and kaempferol. In contrast, kaempferol and quercetin were only taken up at the root tip. Confocal microscopy demonstrated that mid-root or cotyledon applications resulted in flavonoid movement towards the root tip mainly in the vascular tissue. These results indicate that flavonoids can move away from their site of synthesis. Experiments are underway to determine the mechanisms and physiological consequences of this movement.
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1 - The Australian National University, Genomic Interactions Group, ARC Centre for Integrative Legume Research, Research School of Biological Sciences, Canberra, ACT, 2601, Australia
2 - Wake Forest University, Biology
3 - The Australian National University; Research School of Biological Scie, Genomic Interactions Group; ARC Centre for Integrative Legume Research
Keywords:
flavonoid movement systems
aglycone.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P20008
Abstract ID:176 |
