Department of Biology, Princeton University, 08540, Princeton, NJ, USA.
Planta. 1979 Jan;145(4):365-9. doi: 10.1007/BF00388362.
Cloned, cytokinin-habituated tissues of Nicotiana tobacum L. cv. "Havana 425" are able to grow in culture at 25° C without added cytokinin. These tissues vary in their expression of the habituated phenotype at 16° C. When cytokinin-requiring pith tissues are converted to the habituated state by 35° C treatment, all of the habituated cells are cold sensitive. After several transfers in culture, some of these habituated cells give rise to stable, cold resistant variants. Both phenotypes are inherited by individual cells. Cold sensitive clones at 16° C and non-habituated clones at 16° C as well as 25° C show the same dose response to the cytokinin, kinetin. This suggests that at the physiological level, cold sensitivity results from a decreased production of cell division factors rather than from a decreased affinity of cellular receptors for these factors.
克隆的、细胞分裂素驯化的烟草组织能够在 25°C 的培养条件下生长，而无需添加细胞分裂素。这些组织在 16°C 时表现出驯化表型的差异。当需要细胞分裂素的髓组织通过 35°C 处理转化为驯化状态时，所有驯化的细胞对低温敏感。在培养中经过多次转移后，其中一些驯化的细胞会产生稳定的、抗寒的变体。这两种表型都是由单个细胞遗传的。16°C 时的低温敏感克隆和 16°C 及 25°C 时的非驯化克隆对细胞分裂素激动素的剂量反应相同。这表明在生理水平上，低温敏感性是由于细胞分裂因子的产生减少，而不是细胞受体对这些因子的亲和力降低所致。
