MSU/AEC Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823.
Plant Physiol. 1968 May;43(5):827-37. doi: 10.1104/pp.43.5.827.
Application of cytokinins to moss protonemata of the proper physiological age causes bud formation on specific cells (caulonema). During the early stages of their development, buds revert to protonemal filaments if the cytokinin has been removed by washing the protonemata. This indicates that the hormone is not acting as a "trigger" but has to be present during a critical period of time until differentiation is stabilized. Autoradiographs of protonemata treated with a labeled cytokinin, benzyladenine-benzyl-7-(14)C, show a striking accumulation of the radioactivity in caulonema cells which are in the stage of bud formation, and in the buds themselves. Cells which did not react to the hormone contained very little radioactivity. The accumulation of benzyladenine in the "target cells" may be due to the presence of binding sites which, in turn, may distinguish responding cells from non-responding ones.
细胞分裂素应用于具有适当生理年龄的藓原丝体，会导致特定细胞（茎丝体）形成芽。如果通过洗涤原丝体去除细胞分裂素，芽在发育的早期阶段会恢复为原丝体纤维。这表明激素不是作为“触发物”起作用，而是必须在一个关键时期内存在，直到分化稳定下来。用标记的细胞分裂素，苄基腺嘌呤-苄基-7-(14)C 处理的原丝体的放射自显影显示，放射性物质在处于芽形成阶段的茎丝体细胞中以及在芽本身中大量积累。对激素没有反应的细胞含有很少的放射性物质。在“靶细胞”中，苄基腺嘌呤的积累可能是由于存在结合位点，而这些结合位点反过来又可以区分有反应的细胞和没有反应的细胞。
