Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany AS CR, v.v.i., Šlechtitelů 11, CZ-783 71 Olomouc, Czech Republic.
Plant Sci. 2012 May;187:105-12. doi: 10.1016/j.plantsci.2012.02.003. Epub 2012 Feb 10.
The putative role of cytokinins in processes leading to reproductive development of plants was investigated by analysing the shoot apical parts of a winter cultivar of oilseed rape (Brassica napus L. var. oleifera, cv. Górczański). The endogenous cytokinin levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS) in the shoot apices of vegetative plants (grown at 20/17°C with a 16/8h day/night regime) and vernalized plants (56 days at 5/2°C with a 16/8h photoperiod) at different times during floral transition. During vernalization, the content of all isoprenoid cytokinins increased significantly, coinciding well with the onset of the early stages of reproductive development. Cytokinin levels reached their maxima when most of the plants became irreversibly reproductive (after 42 days of cold treatment). cis-Zeatin riboside (unequivocally identified by quadrupole-time-of-flight MS) accounted for ca. 87-89% of the total isoprenoid cytokinin content in control and vernalized plants, whilst N(6)-isopentenyladenosine ( approximately 6% in control and approximately 8% in vernalized plants) and cis-zeatin (approxiamtely 2% in control and approximately 1% in vernalized plants) were the next most abundant cytokinins. In the post-vernalization period, endogenous cytokinin levels decreased, but remained significantly higher in the reproductive plants than in the vegetative controls. These results suggest that cytokinins, especially those of the cis-zeatin type, are involved in vernalization-induced reproductive development of B. napus.
研究了细胞分裂素在植物生殖发育过程中的假定作用，方法是分析冬季油菜（甘蓝型油菜，变种 oleifera，cv. Górczański）品种的茎尖分生组织。通过液相色谱-串联质谱（LC-MS）在营养植物（20/17°C，16/8h 光照/黑暗周期）和春化植物（56 天，5/2°C，16/8h 光周期）的茎尖分生组织中测量内源细胞分裂素水平，在花转化的不同时间。在春化过程中，所有异戊烯基细胞分裂素的含量显著增加，与生殖发育早期阶段的开始非常吻合。细胞分裂素水平在大多数植物不可逆地进入生殖阶段时达到最大值（冷处理 42 天后）。顺式玉米素核苷（通过四极杆飞行时间 MS 明确鉴定）约占对照和春化植物中总异戊烯基细胞分裂素含量的 87-89%，而 N（6）-异戊烯基腺苷（对照中约 6%，春化植物中约 8%）和顺式玉米素（对照中约 2%，春化植物中约 1%）是下一个最丰富的细胞分裂素。在春化后时期，内源细胞分裂素水平下降，但在生殖植物中仍显著高于营养植物。这些结果表明细胞分裂素，特别是顺式玉米素类型，参与了油菜的春化诱导生殖发育。
