| Abstract Detail
Oxidative Stress Mohapatra, Sridev [1], Minocha, Rakesh [2], Minocha, Subhash [3]. Putrescine overproduction changes the oxidative state of poplar cells in culture and aids in aluminum tolerance. The effect of enhanced putrescine metabolism on the oxidative state of poplar (Populus nigra x maximowiczii) cells with enhanced putrescine metabolism was studied. The cell lines used in this study were either transformed with a GUS gene (control) or with a mouse ornithine decarboxylase (mODC) gene; the latter resulted in over-production of putrescine and a concomitant enhancement in its catabolism, and is called HP (high putrescine) line. Activities of some of the important enzymes of the reactive oxygen species (ROS) scavenging machinery were measured over a seven day culture period in the two cell lines. The cellular contents of a common reductant glutathione and amino acids proline and glutamate were also analyzed. Glutathione reductase and monodehydroascorbate reductase activities increased in response to enhanced putrescine metabolism, and the activity of ascorbate reductase remained mostly unchanged. Contents of reduced glutathione were lower in the HP cells. Proline content increased on some days, and glutamate content was lower on all seven days in the HP as compared to the control cells. While no significant difference in the mitochondrial activity was detected, enhanced putrescine metabolism resulted in increased membrane damage in the cells. Treatment with aluminum (a potential inducer of mitochondrial oxidative damage) was better tolerated by the HP cells as compared to controls. We conclude that, while enhanced putrescine metabolism in itself makes poplar cells vulnerable towards increased oxidative damage, high putrescine has a protective role against aluminum toxicity.
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1 - University of New Hampshire, Plant Biology, 46, College Road, Durham, NH, 03824, USA
2 - USDA Forest Service, NERS, Stress Physiology
3 - University of New Hampshire, Plant Biology
Keywords:
polyamines
Putrescine.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P06004
Abstract ID:2506 |
