Analysis of cycles of dormancy and growth in pea axillary buds based on mRNA accumulation patterns of cell cycle-related genes.
Analysis of cycles of dormancy and growth in pea axillary buds based on mRNA accumulation patterns of cell cycle-related genes.
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DOI：
10.1093/oxfordjournals.pcp.a029365
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发表时间：
1998-03
影响因子：
4.9
通讯作者：
Sae Shimizu;H. Mori
中科院分区：
文献类型：
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作者：
Sae Shimizu;H. Mori
豌豆（Pisum sativum L.）CV.阿拉斯加）不生长在完整的植物。去顶后可刺激背腋芽迅速生长。在这里，我们从豌豆中分离出PCNA、cyclinB、cyclinD和cdc2的cDNA。这些基因的mRNA表达水平在休眠腋芽中很低，而在去顶后显著增加。基于这些基因的mRNA积累模式，我们发现休眠腋芽中的大多数细胞被阻滞在细胞周期的G1期。豌豆苗第二节有四个芽。去顶后，大芽和小芽中的mRNA含量均增加，并在随后的3d内保持不变。4d后，大芽中仍有mRNA表达，小芽中已无mRNA表达。然而，在去除大芽后，小芽中的mRNA水平又开始增加。这些mRNA的积累模式与第一次断头后相同。这些结果表明，大多数细胞在腋芽的第二节再次停滞在G1期，并有能力经历多个周期的休眠和生长。此外，原位杂交分析表明，PCNA mRNA增加后，腋芽的所有部分断头。
Axillary buds of pea (Pisum sativum L. cv. Alaska) do not grow on intact plants. Dormant axillary buds can be stimulated to grow rapidly after decapitation. Here, we isolated cDNAs of PCNA, cyclinB, cyclinD, and cdc2 from pea. The mRNA expression levels of these genes were very low in dormant axillary buds, whereas they remarkably increased after decapitation. Based on the mRNA accumulation patterns of these genes, we found that most cells in dormant axillary buds are arrested at the G1 phase in the cell cycle. There are four buds at the second node on pea seedlings. After decapitation, mRNAs became abundant in the large and small buds and were kept during the following 3 d. After 4 d, mRNAs were still present in the large bud, but not in the small bud. However, after removal of the large bud, the mRNA levels started to increase again in the small bud. These mRNA accumulation patterns were the same as those after the first decapitation. These results suggested that most cells in axillary buds at the second node are arrested at the G1 phase again and have the capacity to undergo multiple cycles of dormancy and growth. Moreover, in situ hybridization analyses demonstrated that PCNA mRNA increased in all parts of the axillary buds after decapitation.