Gene expression of ascorbic acid-related enzymes in tobacco
2002; Elsevier BV; Volume: 61; Issue: 6 Linguagem: Inglês
10.1016/s0031-9422(02)00367-9
ISSN1873-3700
AutoresKazufumi Tabata, Takahiko Takaoka, Muneharu Esaka,
Tópico(s)Photosynthetic Processes and Mechanisms
ResumoGDP-d-mannose pyrophosphorylase (GMPase) and l-galactono-1, 4-lactone dehydrogenase (GalLDH) are key enzymes in l-ascorbic acid (AsA) biosynthesis of plants, and a full-length cDNA for GMPase was isolated from tobacco using PCR. Additionally, expression of GMPase, GalLDH and other AsA-related enzymes was examined in tobacco tissues and cultured BY-2 cells, and the relationship between their expression patterns and AsA content is discussed. It was found that the expression of GalLDH and GMPase mRNAs was markedly suppressed by loading AsA, suggesting that AsA concentration in the cells may regulate AsA biosynthesis. Moreover, the expression of GMPase and GalLDH mRNAs in tobacco leaf also suggested that AsA biosynthesis may be induced by light.
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