Botanisches Institut II der Universität, Kaiserstrasse 12, D-7500, Karlsruhe, Federal Republic of Germany.
Planta. 1985 Jan;163(1):91-6. doi: 10.1007/BF00395902.
The lipid composition of whole leaves and isolated plastoglobul of beech (Fagus sylvatica) has been studied during four natural autumnal senescence stages. Chlorophylls, glycolipids, and phospholipids were extensively degraded in leaves. About 20% of the glycolipids found in leaves during summer, however, remained in the last stage of leaf senescence. Triacylglycerols, also detected in large amounts in summer leaves, were hydrolyzed during senescence. The content of free fatty acids derived from degradation of glycerolipids therefore increased. The total carotenoid and prenyl quinone content was largely unchanged during senescence, except during the last stage investigated, but the reduced forms of prenyl quinones decreased while the oxidized prenyl quinones increased. Plastoglobuli isolated from summer leaves mainly contained triacylglycerols, plastohydroquinone, and α-tocopherol. The triacylglycerol content declined in plastoglobuli during senescence. Most of the triacylglycerols must be located outside the plastoglobuli throughout the stages investigated. Carotenoids liberated from thylakoids were esterified and increasingly deposited in plastoglobuli during senescence. In the last senescence stage, carotenoid esters were the main component of plastoglobuli. Prenyl quinones were also transferred into plastoglobuli. Reduced prenyl quinones were sucessively oxidized during senescence and plastoquinone (oxidized) was the predominant prenyl quinone in plastoglobuli isolated from the last senescence stage. The carotenoid and prenyl quinone distribution was identical in leaves and plastoglobuli during late senescence. The main constituents of thylakoids, glycolipids and proteins, were not deposited in plastoglobuli and therefore did not play an important role in plastoglobuli metabolism.
在四个自然秋季衰老阶段研究了山毛榉（Fagus sylvatica）的整叶和分离的质体小球的脂质组成。叶绿素、糖脂和磷脂在叶片中广泛降解。然而，在叶片衰老的最后阶段，夏季叶片中发现的约 20％的糖脂仍然存在。在衰老过程中，三酰基甘油也大量存在于夏季叶片中被水解。因此，甘油脂降解产生的游离脂肪酸含量增加。类胡萝卜素和 prenyl 醌的总含量在衰老过程中基本不变，除了在最后一个阶段，但还原型 prenyl 醌减少，而氧化型 prenyl 醌增加。从夏季叶片中分离出的质体小球主要含有三酰基甘油、质体氢醌和α-生育酚。在衰老过程中，质体小球中的三酰基甘油含量下降。在整个研究阶段，大部分三酰基甘油必须位于质体小球之外。类囊体释放的类胡萝卜素被酯化并在衰老过程中不断沉积在质体小球中。在最后一个衰老阶段，类胡萝卜素酯是质体小球的主要成分。prenyl 醌也被转移到质体小球中。还原型 prenyl 醌在衰老过程中被相继氧化，质体醌（氧化）是从最后一个衰老阶段分离出的质体小球中主要的 prenyl 醌。在晚期衰老阶段，质体小球中的类胡萝卜素和 prenyl 醌分布与叶片中的相同。质体小球代谢中不起重要作用的类囊体的主要成分，如糖脂和蛋白质，没有沉积在质体小球中。
