Newman D W
Botany Department, Miami University, Oxford, Ohio.
Plant Physiol. 1966 Feb;41(2):328-34. doi: 10.1104/pp.41.2.328.
The fatty acids of plastids from several types of mineral-deficient and senescent tissues were analyzed. Incorporation of acetate into long-chain fatty acids of leaf tissue and of plastids from nitrogen-deficient and normal plants was determined. In general, the senescent and nitrogen-deficient chloroplasts contained a higher ratio of saturates to unsaturates than did plastids from younger tissues and from tissues grown on a complete nutrient.Nitrogen-deficient leaf tissue and plastids were capable of rapidly incorporating acetate into some of the fatty acids, especially palmitic and oleic acids. However, the comparative rate of acetate incorporation into linolenic acid in nitrogen-deficient chlorophyllous tissue was less than in tissue grown on a complete nutrient. With the addition of UDP-glucose to a reaction mixture containing added cofactors for noncyclic photosynthetic phosphorylation the relative incorporation of acetate into linolenate as compared to palmitate was increased in both the nitrogen-deficient and normal leaf tissue. This would indicate that nitrogen-deficient tissues have the enzymic systems for forming long-chain fatty acids but that the reduced photosynthesis limits the amount of precursors for the formation of lipids, especially galactolipids. However, nothing is known about the rate of fatty acid degradation under these conditions.
对几种矿物质缺乏和衰老组织的质体脂肪酸进行了分析。测定了乙酸盐掺入叶片组织以及缺氮和正常植物质体的长链脂肪酸中的情况。一般来说，衰老和缺氮的叶绿体中饱和脂肪酸与不饱和脂肪酸的比例高于较幼嫩组织以及在完全营养液中生长的组织的质体。缺氮的叶片组织和质体能够迅速将乙酸盐掺入某些脂肪酸中，尤其是棕榈酸和油酸。然而，缺氮的叶绿素组织中乙酸盐掺入亚麻酸的相对速率低于在完全营养液中生长的组织。在含有用于非循环光合磷酸化的添加辅因子的反应混合物中加入UDP-葡萄糖后，缺氮和正常叶片组织中乙酸盐掺入亚麻酸与棕榈酸的相对比例均增加。这表明缺氮组织具有形成长链脂肪酸的酶系统，但光合作用的降低限制了脂质尤其是半乳糖脂形成的前体数量。然而，在这些条件下脂肪酸降解的速率尚不清楚。
