Transgenic Manipulation of the Metabolism of Polyamines in Poplar Cells

The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra...

Full description

Saved in:
Bibliographic Details
Published in:Plant physiology (Bethesda) 2001-04, Vol.125 (4), p.2139-2153
Main Authors: Pratiksha Bhatnagar, Bernadette M. Glasheen, Suneet K. Bains, Stephanie L. Long, Rakesh Minocha, Walter, Christian, Minocha, Subhash C.
Format: Article
Language:English
Subjects:
Agronomy. Soil science and plant productions
Animals
Arginine - pharmacology
Biochemical Processes and Macromolecular Structures
Biolistics
Biological and medical sciences
Biosynthesis
Cell lines
Cells, Cultured
Complementary DNA
Cycadopsida - cytology
Cycadopsida - metabolism
Economic plant physiology
Enzymes
Fundamental and applied biological sciences. Psychology
Gene expression regulation
Glucuronidase - genetics
Glucuronidase - metabolism
Glutamine - pharmacology
Metabolism
Mice
Nitrogen metabolism
Nitrogen metabolism and other ones (excepting carbon metabolism)
Nutrition. Photosynthesis. Respiration. Metabolism
Ornithine Decarboxylase - genetics
Ornithine Decarboxylase - metabolism
Plant cells
Plant physiology and development
Plants, Genetically Modified - cytology
Plants, Genetically Modified - metabolism
Plasmids
Polyamines
Polyamines - metabolism
Putrescine - metabolism
Recombinant Proteins - metabolism
Spermine - metabolism
Transgenic animals
Transgenic plants
Trees - cytology
Trees - metabolism
Urea - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra × maximowiczii) expressing a mouse Orn decarboxylase (odc) cDNA. The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells. Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation. The addition of urea and glutamine had no effect on polyamines in either of the cell lines. Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells, (b) accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity, (c) Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine, (d) Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells, and (e) assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production.
ISSN:0032-0889
1532-2548
DOI:10.1104/pp.125.4.2139