Differential expression of two fructokinases in Oryza sativa seedlings grown under aerobic and anaerobic conditions
Differential expression of two fructokinases in Oryza sativa seedlings grown under aerobic and anaerobic conditions
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DOI：
10.1007/s10265-006-0281-3
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发表时间：
2006-07-01
影响因子：
2.8
通讯作者：
Alpi, A.
中科院分区：
文献类型：
--
作者：
Guglielminetti, L.;Morita, A.;Alpi, A.
果糖激酶（EC 2.7.1.4）可能在缺氧条件下水稻幼苗碳水化合物代谢中起重要作用。我们在这里介绍了两种水稻果糖激酶，即OsFK1和OsFK2的分子和生化特征。结果表明，在转录和转导水平上，OsFK1在有氧条件下优先表达，而OsFK2在缺氧条件下被诱导表达。OsFK1受到底物抑制，而OsFK2似乎在很大程度上不受果糖浓度高达10 mM的影响。已经提出了缺氧诱导蛋白的糖调节，但我们对不同时间的葡萄糖处理或不处理（10、30或90 mM）的水稻愈伤组织的研究结果表明，OsFK1和OsFK2都不受糖调节。我们认为OsFK2在缺氧条件下的果糖磷酸化中起主要作用。
Fructokinases (EC 2.7.1.4) may play an important role in carbohydrate metabolism of Oryza sativa L. (rice) seedlings under anoxia. We present here the molecular and biochemical characterizations of two rice fructokinases, namely OsFK1 and OsFK2. The results show that, at both a transcriptional and a transductional level, OsFK1 is preferentially expressed under aerobic conditions, whereas OsFK2 is induced under anoxia. Substrate inhibition was demonstrated for OsFK1, while OsFK2 appears to be largely unaffected by fructose concentrations up to 10 mM. Sugar modulation of anoxia-induced proteins has been proposed, but our results on rice calli treated with or without glucose (10, 30 or 90 mM) for different time indicate that neither OsFK1 nor OsFK2 are sugar-regulated. We propose that OsFK2 plays a major role in fructose phosphorylation under anoxic conditions.