菠萝叶膜脂脂肪酸组成的温度效应及其与抗寒性的关系

生长在不同季节的菠萝叶膜脂脂肪酸的配比存在着明显差异;随着大气温度的下降,18:1含量显著减少,18:2和18:3含量增加。不同品种均表现出一致的变化趋势。致害低温破坏了膜脂,使较不抗寒品种的16:0含量增加,18:2和18:3含量减少;较抗寒品种这种变化则较不显著。适当低温锻炼能改变膜脂脂肪酸的代谢过程,16:0和18:1含量减少,18:3含量增加。当处于更低温度时,除了16:0和18:1继续减少外,有一部分18:2也脱饱和而转变为18:3。因之明显地增加了膜脂中18:3的含量和脂肪酸的不饱和度,从而有利于抗寒性的提高。而品种间的抗寒性差异亦是在此低温期间表现出来。

EFFECTS OF TEMPERATURE ON MEMBRANE FATTY ACID COMPOSITION IN LEAVES OF ANANAS COMOSUS (L) MERR. AND THEIR RELATION TO COLD RESISTANCE

The change of composition of membrane fatty acids in the leaves of pineapple during different growing seasons and the relation between such change and the cold resistance were measured.There was a significant difference in composition of membrane fatty acids in the leaves of pineapple during different growing seasons. With the decrease of atmospheric temperature, the content of 18:1 acid significantly decreased, and the contents of 18:2 and 18:3 acids increased. An identical trend was observed in various cultivars. The low injurious temperature destroyed the membrane lipids, causing the change in proportion of the composition of fatty acids: the content of 16:0 increased, the contents of 18:2 and 18:3 decreased. It is especially evident in less cold resistant cultivars. In the process of hardening with low temperature, the biological synthesis of fatty acids was altered: the contents of 16:0 and 18:1 increased and the content of 18:3 increased. When treated with lower temperature, a part of 18:2 was desaturated and turned into 18:3, thus increased the unsaturation of membrane fatty acids and the cold resistance. At the same time, difference in cold resistance was observed in various cultivars.