MEMBRANE DETERIORATION IN SENESCING CARNATION FLOWERS - COORDINATED EFFECTS OF PHOSPHOLIPID DEGRADATION AND THE ACTION OF MEMBRANOUS LIPOXYGENASE
MEMBRANE DETERIORATION IN SENESCING CARNATION FLOWERS - COORDINATED EFFECTS OF PHOSPHOLIPID DEGRADATION AND THE ACTION OF MEMBRANOUS LIPOXYGENASE
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DOI：
10.1104/pp.85.1.204
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发表时间：
1987-09-01
期刊：
影响因子：
7.4
通讯作者：
THOMPSON, JE
中科院分区：
文献类型：
--
作者：
FOBEL, M;LYNCH, DV;THOMPSON, JE
香石竹切花花瓣微粒体膜的脂质流动性随着花的衰老而降低。在膜类脂氧化酶活性活跃的条件下，幼花微粒体膜的体外老化诱导了流动性的类似变化。当膜在脂氧合酶抑制剂的存在下老化或老化前热变性时，流动性没有变化。自然衰老花的膜和体外老化的膜都保持饱和：不饱和脂肪酸比例的增加，这是脂质流动性下降的原因，在这两种情况下，都有证据表明，作为脂氧合酶底物的不饱和脂肪酸、亚油酸和亚麻酸消耗殆尽。脂质磷酸盐的损失反映了膜磷脂的分解，在脂氧合酶样活性引起的不饱和脂肪酸耗尽之前。这些数据被解释为表明脂肪酸底物可通过磷脂降解的起始获得膜相关脂氧化酶样活性，并且这些底物的利用导致膜上不饱和脂肪酸的选择性消耗和随后的散装脂质流动性降低。
The lipid fluidity of microsomal membranes from the petals of cut carnation [Dianthus caryophyllus] flowers decreases as the flowers senesce. A comparable change in fluidity was induced by in vitro aging of microsomal membranes from young flowers under conditions in which membranous lipoxygenase-like activity was active. There was no change in fluidity when the membranes were aged in the presence of inhibitors of lipoxygenase or were heat-denatured prior to aging. Membranes from naturally senesced flowers and membranes that had been aged in vitro both sustained an increase in saturated:unsaturated fatty acid ratio that accounted for the decrease in lipid fluidity, and in both instances there was evidence for depletion of the unsaturated fatty acids, linoleic acid, and linolenic acid, which are substrates for lipoxygenase. Loss of lipid phosphate reflecting breakdown of membrane phospholipids preceded the depletion of unsaturated fatty acids attributable to the lipoxygenase-like activity. The data have been interpreted as indicating that fatty acid substrates for membrane-associated lipoxygenase-like activity are made available by the initiation of phospholipid degradation, and that the utilization of these substrates results in a selective depletion of unsaturated fatty acids from the membrane and an ensuing decrease in bulk lipid fluidity.