| Abstract Detail
Metabolism Smita, Smita [1], Minocha, Rakesh [2], Minocha, Subhash [3]. Enhanced polyamine metabolism and sulfur amino acids in poplar cells. Enhanced polyamine metabolism (via over-expression of a mouse ornithine decarboxylase - mODC gene) was seen to cause a large reduction in the cellular content of two sulfur-containing amino acids methionine (Met) and cysteine + cystine in cell suspension cultures of poplar (Populus nigra x maximowiczii). This was accompanied by a sharp increase in protein accumulation and slowing of growth of these cultures. We investigated the effect of exogenous cysteine (Cys) and Met on the mitochondrial activity and cell growth as well as polyamine (putrescine, spermidine and spermine) contents in the suspension cultures of control (GUS-transgenic) and HP (high putrescine or mODC-transgenic) cells. Addition of either Cys or Met did not have a significant effect on polyamine content of the cells, nor did it affect the mitochondrial activity and the growth of the two cell lines. To check whether inorganic sulfur was being a limiting factor responsible for decrease in sulfur amino acids and the soluble proteins, potassium sulfate was added to the growth medium, and again polyamines and total proteins were analyzed. No significant change in the polyamine content was seen with the addition of inorganic sulfur. The profile of changes in soluble protein content of the cells during the 7 d culture period was also not altered in either cell line by the addition of sulfur. We conclude that enhanced protein synthesis in the HP cells is probably responsible for the decrease in sulfur amino acids, which may then cause a rapid protein breakdown.
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1 - University of New Hampshire, Plant Biology, 46 College Rd, Rudman Hall, Durham, NH, 03824, USA
2 - USDA Forest Service, NERS, Stress Physiology
3 - University of New Hampshire, Plant Biology
Keywords:
polyamine.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P19044
Abstract ID:2505 |
