Williams J P, Khan M U, Mitchell K, Johnson G
Department of Botany and the Centre for Plant Biotechnology, University of Toronto, Toronto, Ontario M5S 1A1, Canada.
Plant Physiol. 1988 Aug;87(4):904-10. doi: 10.1104/pp.87.4.904.
Experiments on the effects of temperature on the levels of unsaturated fatty acids and their rates of desaturation in Brassica napus leaf lipids have shown that significant differences occur in the composition of all diacylglycerols in the leaf between plants grown at high and low temperatures. In the major thylakoid diacylglycerols, monogalactosyl-diacylglycerol and digalactosyldiacylglycerol, not only is there an increase in the level of unsaturation at low temperatures, but there is a change in the balance between molecular species of chloroplastic origin (16/18C) and cytosolic origin (18/18C). Radioactivity tracer data indicate that at low temperatures there are two distinct phases of desaturation in the fatty acids of the major diacylglycerols of these leaves. A rapid phase, which appears in plants grown at low temperatures and results in the desaturation of palmitic acid to hexadecadienoic acid and oleic acid to linoleic acid may explain the high levels of unsaturated fatty acids found in the leaf diacylglycerols from plants grown at low temperatures. The appearance of this rapid phase is controlled by the temperature at which the plant is grown and is not subject to rapid variations in environmental temperature.
关于温度对甘蓝型油菜叶片脂质中不饱和脂肪酸水平及其去饱和速率影响的实验表明，在高温和低温下生长的植株叶片中，所有二酰基甘油的组成存在显著差异。在主要的类囊体二酰基甘油单半乳糖基二酰基甘油和二半乳糖基二酰基甘油中，不仅低温下不饱和水平增加，而且叶绿体来源（16/18C）和胞质来源（18/18C）的分子种类之间的平衡也发生了变化。放射性示踪数据表明，在低温下，这些叶片主要二酰基甘油的脂肪酸存在两个不同的去饱和阶段。一个快速阶段出现在低温下生长的植株中，导致棕榈酸去饱和为十六碳二烯酸，油酸去饱和为亚油酸，这可能解释了低温下生长的植株叶片二酰基甘油中不饱和脂肪酸的高含量。这个快速阶段的出现受植株生长温度的控制，不受环境温度快速变化的影响。
