Division of Environmental Biology, The National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki 305, Japan.
Plant Physiol. 1990 Oct;94(2):766-72. doi: 10.1104/pp.94.2.766.
Molecular species and fatty acid distribution of triacylglycerol (TG) accumulated in spinach (Spinacia oleracea L.) leaves fumigated with ozone (0.5 microliter per liter) were compared with those of monogalactosyldiacylglycerol (MGDG). Analysis of positional distribution of the fatty acids in MGDG and the accumulated TG by the enzymatic digestion method showed that hexadecatrienoate (16:3) was restricted to sn-2 position of the glycerol backbone in both MGDG and TG, whereas alpha-linolenate (18:3) was preferentially located at sn-1 position in MGDG, and sn-1 and/or sn-3 positions in TG, suggesting that 1,2-diacylglycerol moieties of MGDG are the direct precursor of TG in ozonefumigated leaves. Further analysis of TG molecular species by argentation chromatography and mass spectrometry showed that TG increased with ozone fumigation consisted of approximately an equal molar ratio of sn-1,3-18:3-2-16:3 and sn-1,2,3-18:3. Because the molecular species of MGDG in spinach leaves is composed of a similar molar ratio of sn-1-18:3-2-16:3 and sn-1,2-18:3, we concluded that MGDG was converted to 1,2-diacylglycerol and acylated with 18:3 to TG in ozone-fumigated spinach leaves.
用臭氧（0.5 微升/升）熏蒸的菠菜（Spinacia oleracea L.）叶片中积累的三酰基甘油（TG）的分子种类和脂肪酸分布与单半乳糖二酰基甘油（MGDG）进行了比较。通过酶消化法分析 MGDG 和积累的 TG 中脂肪酸的位置分布表明，十六碳三烯酸（16:3）仅位于 MGDG 和 TG 甘油骨架的 sn-2 位，而α-亚麻酸（18:3）优先位于 MGDG 的 sn-1 位，以及 TG 的 sn-1 和/或 sn-3 位，表明 MGDG 的 1,2-二酰基甘油部分是臭氧熏蒸叶片中 TG 的直接前体。通过银染色谱和质谱对 TG 分子种类的进一步分析表明，随着臭氧熏蒸，TG 增加，由 sn-1,3-18:3-2-16:3 和 sn-1,2,3-18:3 摩尔比约相等的组成。由于菠菜叶片中 MGDG 的分子种类由 sn-1-18:3-2-16:3 和 sn-1,2-18:3 的相似摩尔比组成，我们得出结论，在臭氧熏蒸的菠菜叶片中，MGDG 转化为 1,2-二酰基甘油并与 18:3 酰化为 TG。
