Abstract
Arginine (Arg) and ornithine (Orn), both derived from glutamate (Glu), are the primary substrates for polyamine (PA) biosynthesis, and also play important roles as substrates and intermediates of overall N metabolism in plants. Their cellular homeostasis is subject to multiple levels of regulation. Using reverse transcription quantitative PCR (RT-qPCR), we studied changes in the expression of all genes of the Orn/Arg biosynthetic pathway in response to upregulation [via transgenic expression of mouse
Orn decarboxylase (
mODC)] of PA biosynthesis in poplar (
Populus nigra x maximowiczii) cells grown in culture. Cloning and sequencing of poplar genes involved in the Orn/Arg biosynthetic pathway showed that they have high homology with similar genes in other plants. The expression of the genes of Orn, Arg and PA biosynthetic pathway fell into two hierarchical clusters; expression of one did not change in response to high putrescine, while members of the other cluster showed a shift in expression pattern during the 7-day culture cycle.
Keywords
Arginine biosynthesis,
Ornithine biosynthesis,
Gene expression,
Polyamines,
Reverse transcriptase quantitative polymerase chain reaction,
Hierarchical clustering
Citation
Page, Andrew F.; Minocha, Rakesh; Minocha, Subhash C. 2012. Living with high putrescine: expression of ornithine and arginine biosynthetic pathway genes in high and low putrescine producing poplar cells. Amino Acids. 42(1): 295-308.
