Hormonal control of gene expression during reactivation of the cell cycle in tobacco mesophyll protoplasts
Hormonal control of gene expression during reactivation of the cell cycle in tobacco mesophyll protoplasts
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DOI：
10.1007/pl00007038
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发表时间：
1998-09-01
影响因子：
4.8
通讯作者：
Shannon, TA
中科院分区：
文献类型：
--
作者：
Carle, SA;Bates, GW;Shannon, TA
在烟草叶肉原生质体培养的最初48 h内，研究了生长素和细胞分裂素在细胞周期再激活中的作用。使用激素延迟和戒断研究，我们发现生长素需要0-4小时的培养，而细胞分裂素不需要，直到10-12小时，这是6-10小时前的S期。环己酰亚胺阻断分裂，表明需要蛋白质合成。为了检测对这两种激素的分子反应，我们检测了细胞周期标志物cdc 2的表达。Cdc 2的表达在培养12 h时检测到，与细胞分裂素需求的时间一致，并且在进入S.然而，cdc 2部分诱导生长素或细胞分裂素单独，表明cdc 2的表达不是主要目标的激素。我们的激素延迟实验表明，从生长素和细胞分裂素到细胞周期再激活有不同的信号转导途径，并且这些途径在S.这些不同途径的潜在机制仍有待阐明。
The roles of auxin and cytokinin in cell cycle reactivation were studied during the first 48 h of culture of mesophyll protoplasts of Nicotiana tabacum. Using hormone delay and withdrawal studies we found that auxin was required by 0-4 h of culture, whereas cytokinin was not required until hour 10-12, which is 6-10 h before S phase. Cycloheximide blocks division, indicating that protein synthesis is required. In an effort to detect a molecular response to either hormone, we examined the expression of the cell cycle marker, cdc2. Cdc2 expression was detected by 12 h of culture, coincident with the timing of the cytokinin requirement and well before the entry into S. However, cdc2 was partially induced by either auxin or cytokinin alone, suggesting that cdc2 expression is not the primary target of either hormone. Our hormone delay experiments suggest that there are separate signal transduction pathways leading from auxin and from cytokinin to reactivation of the cell cycle and that these pathways converge before S. The underlying mechanisms for these distinct pathways remain to be elucidated.