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绿豆子叶衰老期间核酸代谢的变化

文江祁, 梁厚果

兰州大学植物生理研究室

摘要

萌发绿豆的子叶自然衰老期间, 核酸含量降低, RNA降低的幅度比DNA大。电 泳分析结果表明，子叶衰老期间细胞核主带DNA明显降低; 迁移慢的卫星带DNA 变化不大。在RNA各组分中，18SrRNA从衰老前期就开始降低; 25SrRNA和4—5S小 分子RNA到衰老后期才缓慢下降。DNase和Rnase活性在子叶整个衰老期间都明显 升高, 是导致核酸含量下降的主要原因。~(3)H- 核苷掺入试验表明, 核酸 的合成速率在子叶衰老前期有所上升, 到衰老后期又降低。Poly(A)~(+)-mRNA 含量在子叶开始衰老时期明显上升。图7参21

关键词： 绿豆; 子叶; 衰老; 核酸代谢

Changes in metabolism of nucleic acids during senescence of mung bean cotyledons

Wen Jiangqi, Liang Houguo

Lab. Plant Physiol., Lanzhou Univ.

Abstract

The contents of both DNA and RNA decreased during the senescence of mung bean cotyledons (Fig. 1). Electrophoresis analysis indicated that the decline of nuclear DNA and 18 S rRNA was responsible for the decrease of DNA and RNA levels, respectively (Fig. 2,3). During incipient senescence (2 to 3 days), the contents of poly(A) super(+)-mRNA increased markedly (Fig. 5). The synthetic rates of nucleic acids were tested by super(3)H-nucleoside incorporation. It was shown that in the early stage of senescence (3 to 4 days), the synthesis of nucleic acids increased obviously, expecially RNA (Fig. 7). This gave an implication that the early decline of total nucleic acid levels was not due to the failure of synthesis. The results from the determination of DNase and RNase activities showed that the enhancedhydrolysis of nucleic acids was the main cause of the decline of total nucleic acid levels.

Key words: Mung bean;Cotyledons;Senescenc;Nucleic acid metabolism

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引用本文：

文江祁, 梁厚果. 绿豆子叶衰老期间核酸代谢的变化[J]. 生理学报 1991; 43 (2): .

Wen Jiangqi, Liang Houguo. Changes in metabolism of nucleic acids during senescence of mung bean cotyledons. Acta Physiol Sin 1991; 43 (2): (in Chinese with English abstract).