PHOSPHATIDYLCHOLINE SYNTHESIS - DIFFERING PATTERNS IN SOYBEAN AND CARROT
PHOSPHATIDYLCHOLINE SYNTHESIS - DIFFERING PATTERNS IN SOYBEAN AND CARROT
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DOI：
10.1104/pp.88.3.854
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发表时间：
1988-11-01
期刊：
影响因子：
7.4
通讯作者：
MUDD, SH
中科院分区：
文献类型：
--
作者：
DATKO, AH;MUDD, SH
胡萝卜(Daucus carota L.)组织培养制剂生物合成磷脂酰胆碱的甲基化步骤和大豆(Glyine Max)，以及大豆叶圆片的致病作用。样品与示踪浓度的L-[3H3C]蛋氨酸孵育，在短时间孵育后，观察磷甲基乙醇胺、磷脂二甲基乙醇胺、磷胆碱、磷脂酰甲基乙醇胺、磷脂酰二甲基乙醇胺、磷脂酰胆碱、二甲基乙醇胺和胆碱中放射性出现的动力学。对于大豆(组织培养或叶片)，初始甲基化利用磷乙醇胺作为底物，形成磷甲基乙醇胺。后者转化为磷脂酰甲基乙醇胺，再依次甲基化为磷脂酰二甲基乙醇胺和磷脂酰胆碱。对于胡萝卜，同样，最初的甲基化是磷乙醇胺。随后的甲基化发生在磷基和磷脂酰基水平上。这两种模式都不同于以前在Lemna(SH Mudd，AH Datko 1986 Factory Physiol 82：126-135)中展示的模式，在Lemna中，所有三种甲基化都发生在磷酸碱基水平。对于大豆和胡萝卜，不排除磷脂酰乙醇胺初始甲基化的一些额外贡献。这些结果，加上用水分胁迫下的大麦叶片(WD Hitz，D Rhodes，AD Hanson 1981 Factory Physiol 68：814-822)和盐化甜菜叶片(AD Hanson，D Rhodes 1983 Factory Physiol 71：692-700)所做的类似实验的结果表明，在高等植物中，磷脂酰胆碱的某些甚至全部合成是通过一个共同的提交步骤(将磷乙醇胺转化为磷甲基乙醇胺)进行的，然后是不同植物的甲基化模式。
The methylation steps in the biosynthesis of phosphatidylcholine by tissue culture preparations of carrot (Daucus carota L.) and soybean (Glycine max), and by soybean leaf discs, have been studied. Preparations were incubated with tracer concentrations of L-[3H3C]methionine and the kinetics of appearance of radioactivity in phosphomethylethanolamine, phosphodimethylethanolamine, phosphocholine, phosphatidylmethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, methylethanolamine, dimethylethanolamine, and choline followed at short incubation times. With soybean (tissue culture or leaves), an initial methylation utilizes phosphoethanolamine as substrate, forming phosphomethylethanolamine. The latter is converted to phosphatidylmethylethanolamine, which is successively methylated to phosphatidyldimethylethanolamine and to phosphatidylcholine. With carrot, again, an initial methylation is of phosphoethanolamine. Subsequent methylations occur at both the phospho-base and phosphatidyl-base levels. Both of these patterns differ qualitatively from that previously demonstrated in Lemna (SH Mudd, AH Datko 1986 Plant Physiol 82: 126-135) in which all three methylations occur at the phospho-base level. For soybean and carrot, some added contribution from initial methylation of phosphatidylethanolamine has not been excluded. These results, together with those from similar experiments carried out with water-stressed barley leaves (WD Hitz, D Rhodes, AD Hanson 1981 Plant Physiol 68: 814-822) and salinized sugarbeet leaves (AD Hanson, D Rhodes 1983 Plant Physiol 71: 692-700) suggest that in higher plants some, perhaps all, phosphatidylcholine synthesis occurs via a common committing step (conversion of phosphoethanolamine to phosphomethylethanolamine) followed by a methylation pattern which differs from plant to plant.