Laroche A, Hopkins W G
Department of Plant Sciences, University of Western Ontario, London, Ontario Canada N6A 5B7.
Plant Physiol. 1987 Feb;83(2):371-6. doi: 10.1104/pp.83.2.371.
Cytoplasmic polysomes have been prepared from mature leaves of winter rye (Secale cereale L. cv Puma). This is the first time a method has been developed for isolation of highly polymerized polysomes from mature leaves. The degree of intactness of isolated plant polysomes has been determined by two independent but complementary methods: size class distribution by sucrose gradient centrifugation and in vitro translation. The polymerization of isolated polysomes was estimated by the ratio of the proportion of large polysomes to the proportion of small polysomes obtained from the profiles. Our results show that the composition of the optimal polysome isolation buffer for mature rye leaves is different from that reported for young tobacco and pea leaves. Polysomes were translated in vitro with the S-105 wheat germ fraction. The degree of polysome polymerization has a significant effect on their in vitro translation since both the incorporation of amino acid and the presence of high molecular weight polypeptides are proportional to the large polysomes/small polysomes ratio. This study emphasizes the need to evaluate isolation conditions carefully before proceeding with polysome studies in any particular tissue or in tissues under different physiological status.
已从冬黑麦（Secale cereale L. cv Puma）的成熟叶片中制备了细胞质多核糖体。这是首次开发出从成熟叶片中分离高度聚合多核糖体的方法。已通过两种独立但互补的方法确定了分离出的植物多核糖体的完整程度：通过蔗糖梯度离心法测定大小分级分布以及进行体外翻译。通过从图谱中获得的大多核糖体比例与小多核糖体比例的比值来估算分离出的多核糖体的聚合情况。我们的结果表明，成熟黑麦叶片最佳多核糖体分离缓冲液的组成与已报道的幼嫩烟草和豌豆叶片的不同。用S - 105小麦胚提取物对多核糖体进行体外翻译。多核糖体的聚合程度对其体外翻译有显著影响，因为氨基酸掺入量和高分子量多肽的存在都与大多核糖体/小多核糖体的比例成正比。本研究强调在对任何特定组织或处于不同生理状态的组织进行多核糖体研究之前，需要仔细评估分离条件。
