Abstract

Absolute and relative content and composition of fatty acids, total lipids, and phospholipids, as principal constituents of cell membranes, were examined on vegetative buds of deciduous trees and shrubs throughout the summer and autumn–winter seasons under climatic conditions of the cryolithozone of Yakutia. Lipid metabolism was found to play an essential role in plants' adaptation to low autumnal and winter temperatures in the permafrost zone of Yakutia. The content of phosphatidylcholine in leaf buds of the birch Betula pendula Roth and the shrub Alnus alnobetula subsp. fruticosa (Rupr.) Raus increased throughout the observation period from 9.9 to 23.4 mg/g dry wt. In the autumn–winter period, the composition of fatty acids in the bud lipids of both species was characterized by a high content of unsaturated C18:2 and C18:3 acids. Biosynthesis of fatty acids in buds of deciduous trees and shrubs at a low temperature was apparently controlled by ω3-desaturase, whose activity elevated the content of α-linolenic acid from 2.9 to 5.7 mg/g in B. pendula and from 1.6 to 4.8 mg/g dry wt in A. alnobetula subsp. fruticosa. The seasonal decrease in air temperature was accompanied by an increase in the unsaturation coefficient (k) from 0.9 to 2.3 in B. pendula and from 1.4 to 1.8 in A. alnobetula subsp. fruticosa. It is proposed that the high content of polyunsaturated fatty acids in the autumn–winter period in vegetative buds of the examined woody plants is determined by a complex of climatic factors of the permafrost zone, such as a sharply contrasting day and night temperatures during plant dormancy, extremely low air temperature in winter (down to –60°С), and a short daylight period at this time of the year.

中文翻译：

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西南桦（Betula pendula Roth）和nu木亚种（Alnus alnobetula subsp。）叶芽中脂质及其脂肪酸的季节性动态 低温区条件下的金银花（Rupr。）Raus

摘要

在雅库特（Yakutia）冰冻带气候条件下，在整个夏季和秋季至冬季，在落叶树和灌木的营养芽上检查了脂肪酸，总脂质和磷脂（作为细胞膜的主要成分）的绝对和相对含量及组成。在雅库特的多年冻土带中，脂质代谢在植物适应秋季和冬季低温时起着重要作用。桦木Bethula pendula Roth和灌木Alnus alnobetula亚种的叶芽中磷脂酰胆碱的含量。金露梅（Rupr。）在整个观察期内，Raus从9.9增至23.4 mg / g干重。在秋冬季，两种物种的芽脂中的脂肪酸组成都以高含量的不饱和C18：2和C18：3酸为特征。ω3-去饱和酶明显地控制了低温下落叶乔木和灌木芽中脂肪酸的生物合成，ω3-去饱和酶的活性使摆锤双歧杆菌中α-亚麻酸的含量从2.9mg / g增加到了5.7mg / g ，从1.4mg增加到了4.8mg / g alnobetula亚种中的干wt 金露梅。气温的季节性下降伴随着悬钩子的不饱和系数（k）从0.9增加到2.3，在悬钩子中从1.4增加到1.8。拟南芥亚种 金露梅。有人提出，在被检查的木本植物的营养芽中，秋冬期间多不饱和脂肪酸的含量高是由多年冻土带的多种气候因素决定的，例如植物休眠期间白天和夜晚的温度形成鲜明对比。 ，冬季气温极低（低至–60°С），并且每年的这个时候的白天较短。