Adventitious root growth and cell-cycle induction in deepwater rice
Adventitious root growth and cell-cycle induction in deepwater rice
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DOI：
10.1104/pp.119.1.21
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发表时间：
1999-01-01
期刊：
影响因子：
7.4
通讯作者：
Sauter, M
中科院分区：
文献类型：
--
作者：
Lorbiecke, R;Sauter, M
深水水稻（Oryza sativa）适应长时间的严重洪水条件。在这一时期，不定根的发育提供水、营养和锚。在本研究中，乙烯可以诱导不定根的生长，而生长素、细胞分裂素和赤霉素不能诱导不定根的生长。浸没后8 ~ 10 h，根系伸长有所增加。S期细胞数量和S期特异性组蛋白H3基因的表达在4 ~ 6 h内增加，cz期细胞数量在6 ~ 8 h内增加。细胞周期激活伴随着cdc2激活激酶同源物（R2）的顺序诱导，其中两个cdc2基因（cdc2o -1和cdc2o -2）和三个周期蛋白基因（cycA1）；3, cycB2;1、cycB2；2，但仅诱导R2基因表达先于诱导S期，可能在G1期参与细胞周期调控。在DNA复制过程中，两种cdc2基因的表达水平略高。a型细胞周期蛋白转录本在S期和G2期积累，b型细胞周期蛋白转录本在G2期积累。细胞周期蛋白的表达在所有节点上都有相似的时间过程，这表明乙烯的作用是系统性的，根原基在发育早期就对乙烯有反应。
Deepwater rice (Oryza sativa) is adapted to survive conditions of severe flooding over extended periods of time. During such periods adventitious roots develop to provide water, nutrients, and anchorage. In the present study the growth of adventitious roots was induced by treatment with ethylene but not auxin, cytokinin, or gibberellin. Root elongation was enhanced between 8 and 10 h after submergence. The population of cells in the S phase and expression of the S-phase-specific histone H3 gene increased within 4 to 6 h. Within 6 to 8 h the CZ-phase population increased. Cell-cycle activation was accompanied by sequential induction of a cdc2-activating kinase homolog, R2, of two cdc2 genes, cdc2Os-1 and cdc2Os-2, and of three cyclin genes, cycA1;3, cycB2;1, and cycB2;2, but only induction of the R2 gene expression preceded the induction of the S phase, possibly contributing to cell-cycle regulation in the G1 phase. Both cdc2 genes were expressed at slightly higher levels during DNA replication. Transcripts of the A-type cyclin accumulated during the S and G2 phases, and transcripts of the B-type cyclins accumulated during the G2 phase. Cyclin expression was induced at all nodes with a similar time course, suggesting that ethylene acts systemically and that root primordia respond to ethylene at an early developmental stage.