Activation of cell proliferation by brassinolide application in tobacco BY-2 cells: effects of brassinolide on cell multiplication, cell-cycle-related gene expression, and organellar DNA contents
Activation of cell proliferation by brassinolide application in tobacco BY-2 cells: effects of brassinolide on cell multiplication, cell-cycle-related gene expression, and organellar DNA contents
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DOI：
10.1093/jxb/erg312
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发表时间：
2003-12-01
影响因子：
6.9
通讯作者：
Yoshida, S
中科院分区：
文献类型：
--
作者：
Miyazawa, Y;Nakajima, N;Yoshida, S
类甾醇（BRs）是植物生长和发育中的许多过程所必需的甾体植物激素，如细胞扩增、维管分化和对胁迫的响应。BR对细胞分裂的影响尚不清楚，这一点已被相互矛盾的已发表结果所证实。为了确定BR对细胞分裂的影响，使用烟草（Nicotiana tabacum）BY-2细胞系，其是植物细胞生物学中广泛使用的模型系统。发现油菜素（BL）仅在培养的早期阶段和不存在生长素（2，4-D）的情况下促进细胞分裂。这种细胞分裂的促进作用通过RNA凝胶印迹分析证实。细胞周期相关基因探针。在BL-供应和2，4-D-供应的BY-2细胞的培养期的后期，观察到细胞增殖和细胞周期相关基因表达的差异。此外，BL处理的BY-2细胞与2，4-D处理的细胞具有形态学差异。为了确定是否抑制细胞器DNA复制限制这种促进细胞分裂在早期培养阶段，这种复制进行了检查，发现BL治疗激活细胞器（质体和线粒体）DNA合成没有影响。作为优先的细胞器DNA的合成，这是激活的2，4-D，是必要的，在连续的细胞分裂BY-2细胞，这些数据表明，BL处理的促进细胞分裂的机制是不同的生长素和细胞分裂素的平衡调节。
Brassinosteroids (BRs) are steroidal phytohormones that are essential for many processes in plant growth and development, such as cell expansion, vascular differentiation, and responses to stress. The effects of BRs on cell division are unclear, as attested by contradictory published results. To determine the effect of BRs on cell division, the tobacco (Nicotiana tabacum) BY-2 cell line, which is a widely-used model system in plant cell biology, was used. It was found that brassinolide (BL) promoted cell division only during the early phase of culture and in the absence of auxin (2,4-D). This promotion of cell division was confirmed by RNA gel blot analyses using. cell-cycle-related gene probes. At later stages in the culturing periods of BL-supplied and 2,4-D-supplied BY-2 cells, differences in cell multiplication and cell-cycle-related gene expression were observed. Moreover, the BL-treated BY-2 cells had morphological differences from the 2,4-D-treated cells. To determine whether suppressed organellar DNA replication limited this promotion of cell division during the early culture phase, this replication was examined and it was found that BL treatment had no effect on activating organellar (plastid- and mitochondrial-) DNA synthesis. As preferential organellar DNA synthesis, which is activated by 2,4-D, is necessary during successive cell divisions in BY-2 cells, these data suggest that the mechanism of the promotion of cell division by BL treatment is distinct from that regulated by the balance of auxin and cytokinin.