Induction of a carbon-starvation-related proteolysis in whole maize plants submitted to light/dark cycles and to extended darkness
Induction of a carbon-starvation-related proteolysis in whole maize plants submitted to light/dark cycles and to extended darkness
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DOI：
10.1104/pp.117.4.1281
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发表时间：
1998-08-01
期刊：
影响因子：
7.4
通讯作者：
Raymond, P
中科院分区：
文献类型：
--
作者：
Brouquisse, R;Gaudillère, JP;Raymond, P
三周龄玉米（Zea mays L.）使植物经历光/暗循环和延长的黑暗以研究在整个植物的不同部分中糖限制效应的发生。可溶性糖随着光/暗周期波动，并在延长的黑暗期间急剧下降。长时间黑暗后，在成熟的根，根尖，和幼叶中的蛋白质水平显着下降。谷氨酰胺和天冬酰胺（Asn）的变化相反，与Asn增加在黑暗中。长时间黑暗后，Asn的增加占蛋白质分解释放的氮的大部分。使用针对先前描述的液泡根蛋白酶的多克隆抗体（F.拉梅斯河布鲁基斯角Suire，A. Pradet，P. Raymond [1996] Biochem J 320：283-292）或20 S蛋白酶体，我们表明蛋白水解活性的增加与根中液泡蛋白酶的富集有关，而根或叶中20 S蛋白酶体的量没有变化。我们的研究结果表明，没有显着的净蛋白水解诱导在任何部分的植物在正常的光/暗周期，虽然在代谢和生长的变化出现后不久开始的黑暗时期，饥饿相关的蛋白水解可能会出现在长期的黑暗早于在水槽比成熟组织。
Three-week-old maize (Zea mays L.) plants were submitted to light/dark cycles and to prolonged darkness to investigate the occurrence of sugar-limitation effects in different parts of the whole plant. Soluble sugars fluctuated with light/dark cycles and dropped sharply during extended darkness. Significant decreases in protein level were observed after prolonged darkness in mature roots, root tips, and young leaves. Glutamine and asparagine (Asn) changed in opposite ways, with Asn increasing in the dark. After prolonged darkness the increase in Asn accounted for most of the nitrogen released by protein breakdown. Using polyclonal antibodies against a vacuolar root protease previously described (F. lames, R. Brouquisse, C. Suire, A. Pradet, P. Raymond [1996] Biochem J 320: 283-292) or the 20S proteasome, we showed that the increase in proteolytic activities was related to an enrichment of roots in the vacuolar protease, with no change in the amount of 20S proteasome in either roots or leaves. Our results show that no significant net proteolysis is induced in any part of the plant during normal light/dark cycles, although changes in metabolism and growth appear soon after the beginning of the dark period, and starvation-related proteolysis probably appears in prolonged darkness earlier in sink than in mature tissues.