Plant cells express telomerase activity upon transfer to callus culture, without extensively changing telomere lengths
Plant cells express telomerase activity upon transfer to callus culture, without extensively changing telomere lengths
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DOI：
10.1007/s004380050918
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发表时间：
1998-12-01
期刊：
影响因子：
--
通讯作者：
Matyásek, R
中科院分区：
文献类型：
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作者：
Fajkus, J;Fulnecková, J;Matyásek, R
研究了烟草细胞去分化和分化过程中端粒长度和端粒酶活性的变化；利用叶片组织培养愈伤组织，诱导愈伤组织再生植株。虽然端粒长度范围在去分化和分化过程中没有明显变化，但与源叶片相比，愈伤组织的端粒酶活性明显增加，而源叶片的端粒酶活性几乎无法检测到。再生植株叶片端粒酶活性下降到与原植株基本相同的水平，平均为愈伤组织的0.04%。然后使用再生剂作为源材料重复该过程。在第二轮去分化和分化中，端粒酶活性在再生植株愈伤组织中表现出类似的增加，而在这些愈伤组织中再生植株中表现出下降。愈伤组织和再生体叶片的端粒长度保持不变。在反复的去分化和分化过程中，端粒长度的保守性与细胞分裂速率的剧烈变化和端粒酶活性的相应变化有关，这可能反映了植物细胞中存在一种调节机制，通过控制端粒酶的作用来补偿端粒DNA的复制损失。
Changes in telomere lengths and telomerase activity in tobacco cells were studied during dedifferentiation and differentiation; leaf tissues were used to initiate callus cultures, which were then induced to regenerate plants. While no significant changes in the range of telomere lengths were observed in response to dedifferentiation and differentiation, there was a conspicuous increase in telomerase activity in calli compared to the source leaves, where the activity was hardly detectable. In leaves of regenerated plants, the telomerase activity fell to almost the same level as in the original plant, showing on the average 0.04% of the level in callus. The process was then repeated using the regenerants as the source material. In the second round of dedifferentiation and differentiation, telomerase activity showed a similar increase in calli derived from regenerated plants and a drop in plants regenerated from these calli. Telomere lengths remained unchanged both in calli and in leaves of regenerants. The conservation of telomere lengths over repeated rounds of dedifferentiation and differentiation, which are associated with dramatic changes in cell division rate and corresponding variation in telomerase activity may reflect the function of a regulatory mechanism in plant cells which controls telomerase action to compensate for replicative loss of telomeric DNA.