| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Research Abstract |
(1) CTP : phosphoethanolamine cytidylyltransferase (EC2.7.7.14, ECT) is a rate-limiting enzyme in the biosynthesis of phosphatidylethanolamine in plant cells. I have cloned a cDNA for Arabidopsis ECT by PCR, using primers designed from Arabidopsis genome databases (Accession no. g3786005).
(2) A cDNA for Brassicanapus CTP : phosphocholine cytidylyltransferase (EC2.7.7.15, CCT) library was introduced into Arabidopsis thaliana by an inplanta transformation method. One of transformants showed changes in the levels of phospholipids. Correlation between the changes in the lipid composition and frost resistance is under investigation.
(3) INY102B/YCpGPSS was transformed with the pFL61 (URA3) cDNA library constructed from roots of Brassica napus. From 1 x 10^6 Ura^+ transformants, 100 Etn^+ transformants were isolated, and 16 of them were characterized. They are all identical and a representative clone contained 1,894 bp with an open-reading frame of 1,473 bp. Deduced amino-acid sequence contained 490 amino-acid residues with a calculated molecular mass of 55,153. A homologous Arabidopsis cDNA clone identified by a BLAST search to Arabidopsis EST sequences was also characterized. The Arabidopsis clone contained 1,739 bp with an open-reading frame of 1,449 bp. Deduced amino-acid sequence contained 482 amino-acid residues with a calculated molecular mass of 54,153. Search for homology in GenBank nucleotide sequence database revealed that both clones are homologous to pyridoxal-5'-phosphate-dependent histidine decarboxylases, and a putative pyridoxal phosphate-binding motif for Group II decarboxylases (Sandmeier et al. 1994) was conserved in both proteins. Therefore, our results are the first to suggest that histamine could be synthesized in plant roots.
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