Poster: Late and Moved Abstracts
Abs #
1010: Differential expression of a poplar copper chaperone gene under various abiotic stresses
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Presenter: |
Lee, Hyoshin , hslee@foa.go.kr |
Authors | Lee, Hyoshin (A) Lee, Jae Soon (A) Bae, Eun Kyung (A) Choi, Young Im (A) Noh, Eun W. (A) | | Affiliations: |
(A): Korea Forest Research Institute
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Copper chaperone (CCH) is known to be upregulated during leaf senescence suggesting that they mobilize certain metal ions in leaves and transport them to other growing parts of the plants. It is also involved in defense mechanism against oxidative stress. PoCCH (Populus copper chaperone gene) has been cloned from poplar suspension cells and shown to be expressed upon various treatments including heavy metals, plant growth regulators, and abiotic stresses. The PoCCH cDNA was 540 bp in length, including a 55 bp 5กฏ noncoding domain, 258 bp open reading frame, and 227 bp 3กฏ termination. The coding region of PoCCH represented a putative 85 amino acid protein with molecular weight of 8.9 kDa. The deduced amino acids sequence of PoCCH was 87% and 78% identical to those of tomato and Arabidopsis, respectively. As expected, it exhibited high degree conservation in both the metal-binding and the lysine-rich regions. However, PoCCH does not have a C-terminal extension identified in Arabidopsis CCH gene. Southern blot analysis suggested that the PoCCH gene is present in low copy number in poplar. The expression of PoCCH was down regulated by high level of copper. Whereas some heavy metals like Al and Zn markedly induced PoCCH, others including Cd, Co and Pb had little effect on the expression of the gene. The plant growth regulator JA caused the increase in the PoCCH transcript whereas ABA, SA and GA3 did not. The gene is highly induced when the cells were exposed to high rpm on a gyratory shaker as a physical stress. Also effective inducers of the gene expression in suspension culture were methyl viologen and NaCl. The results indicate that the PoCCH is differentially responded to heavy metals and that JA may be involved in regulating the expression of the gene in poplar cells.
