CELL-CYCLE REGULATION DURING GROWTH-DORMANCY CYCLES IN PEA AXILLARY BUDS
CELL-CYCLE REGULATION DURING GROWTH-DORMANCY CYCLES IN PEA AXILLARY BUDS
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DOI：
10.1007/bf00043650
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发表时间：
1995-10-01
影响因子：
5.1
通讯作者：
STAFSTROM, JP
中科院分区：
文献类型：
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作者：
DEVITT, ML;STAFSTROM, JP
在PEA（pisum sativumcv。Alaska）的豌豆中，分析了与组蛋白H2a和H4，核糖体蛋白基因RPL27和RPL34，MAP激酶，CDC2激酶和细胞周期蛋白B的MRNA的积累模式。这些mRNA的水平在完整植物的休眠芽中较低，当芽通过斩首以斩首末端芽生长时增加，当芽停止生长并变得休眠时减少，然后当芽再次开始生长时增加。流式细胞仪用于确定这些发育过渡期间的核DNA含量。休眠的芽中包含g（1）和g（2）核（约3：1比），但只有低水平的S相核。假设休眠芽中的细胞在细胞周期的三个点，中间G（1），g（1）/s边界和S/C-2边界附近。基于组蛋白H2a和H4 mRNA的积累，它们是S相的标记，在脱腐液后的一小时内，在g（1）/s边界处被捕的细胞输入S。在第一个峰后6小时，组蛋白mRNA积累的第二个峰值表示，在G中间（1）中停滞的细胞群存在。基于Cyclin B mRNA的积累，G（2）晚期（2）和有丝分裂的标记，在脱腐蚀后在G（1）/s上捕获的细胞开始在12至18 h之间分裂。斩首后6小时，细胞周期蛋白B mRNA的水平略有增加可能代表在S/G（2）边界附近被捕的细胞的有丝分裂。 MAP激酶，CDC2激酶，RPL27和RPL34 mRNA的积累与细胞增殖相关，但与细胞周期的特定相无关。
Accumulation patterns of mRNAs corresponding to histones H2A and H4, ribosomal protein genes rpL27 and rpL34, MAP kinase, cdc2 kinase and cyclin B were analyzed during growth-dormancy cycles in pea (Pisum sativum cv. Alaska) axillary buds. The level of each of these mRNAs was low in dormant buds on intact plants, increased when buds were stimulated to grow by decapitating the terminal bud, decreased when buds ceased growing and became dormant, and then increased when buds began to grow again. Flow cytometry was used to determine nuclear DNA content during these developmental transitions. Dormant buds contain G(1) and G(2) nuclei (about 3:1 ratio), but only low levels of S phase nuclei. It is hypothesized that cells in dormant buds are arrested at three points in the cell cycle, in mid-G(1), at the G(1)/S boundary and near the S/C-2 boundary. Based on the accumulation of histone H2A and H4 mRNAs, which are markers for S phase, cells arrested at the G(1)/S boundary enter S within one hour of decapitation. The presence of a cell population arrested in mid-G(1) is indicated by a second peak of histone mRNA accumulation 6 h after the first peak. Based on the accumulation of cyclin B mRNA, a marker for late G(2) and mitosis, cells arrested at G(1)/S begin to divide between 12 and 18 h after decapitation. A small increase in the level of cyclin B mRNA at 6 h after decapitation may represent mitosis of the cells that had been arrested near the S/G(2) boundary. Accumulation of MAP kinase, cdc2 kinase, rpL27 and rpL34 mRNAs are correlated with cell proliferation but not with a particular phase of the cell cycle.