Cytokinins in shoot apices of Brassica napus plants during vernalization

摘要: Abstract The putative role of cytokinins in processes leading to reproductive development plants was investigated by analysing the shoot apical parts a winter cultivar oilseed rape ( Brassica napus L. var. oleifera , cv. Gorczanski). endogenous cytokinin levels were measured liquid chromatography–tandem mass spectrometry (LC–MS) apices vegetative (grown at 20/17 °C with 16/8 h day/night regime) and vernalized (56 days 5/2 °C photoperiod) different times during floral transition. During vernalization, content all isoprenoid increased significantly, coinciding well onset early stages development. Cytokinin reached their maxima when most became irreversibly (after 42 cold treatment). cis -Zeatin riboside (unequivocally identified quadrupole-time-of-flight MS) accounted for ca. 87–89% total control plants, whilst N 6 -isopentenyladenosine (∼6% ∼8% plants) -zeatin (∼2% ∼1% next abundant cytokinins. In post-vernalization period, decreased, but remained significantly higher than controls. These results suggest that cytokinins, especially those type, are involved vernalization-induced B. .