TY - JOUR
T1 - Cytokinins in Rosa hybrida in relation to bud break.
AU - Dieleman, J.A.
AU - Verstappen, F.W.A.
AU - Nicander, B.
AU - Kuiper, D.
AU - Tillberg, E.
AU - Tromp, J.
PY - 1997
Y1 - 1997
N2 - To assess the role of endogenous cytokinins in growth and development of Rosa hybrida, their concentrations in bleeding sap and in roots, stem, leaves, axillary shoots and bottom breaks in three stages of development were quantified. Cytokinins were purified by means of immunoaffinity chromatography and HPLC, and identified by retention time, UV spectrum and GC‐MS. The major translocation form in the xylem was zeatin riboside (ZR). In all mature tissues, cytokinins of the zeatin‐type were predominant, amounting to 80–90% of the total cytokinin concentration. The stems contained high concentrations of cytokinins, probably caused by lateral movement of ZR from the xylem to adjacent stem tissue and the ability of the stem to metabolize cytokinins. In young leaves the contribution of isopentenyl adenine (iP)‐type cytokinins to the total cytokinin pool was about 50%, indicating that these leaves might be capable of de novo synthesis of cytokinins. In older leaves, the concentration of an unidentified cytokinin‐like compound increased to more than 50% of total cytokinins. This compound, which was also found in the roots, might be a storage form of cytokinins. In young axillary shoots, about 50% of the cytokinins are iP‐compounds, suggesting either import of iP‐type cytokinins via the phloem or de novo synthesis of cytokinins. In buds forming bottom breaks, ZR and zeatin riboside monophosphate (ZRMP) are the main cytokinins, indicating that these buds receive their cytokinins from the roots.
AB - To assess the role of endogenous cytokinins in growth and development of Rosa hybrida, their concentrations in bleeding sap and in roots, stem, leaves, axillary shoots and bottom breaks in three stages of development were quantified. Cytokinins were purified by means of immunoaffinity chromatography and HPLC, and identified by retention time, UV spectrum and GC‐MS. The major translocation form in the xylem was zeatin riboside (ZR). In all mature tissues, cytokinins of the zeatin‐type were predominant, amounting to 80–90% of the total cytokinin concentration. The stems contained high concentrations of cytokinins, probably caused by lateral movement of ZR from the xylem to adjacent stem tissue and the ability of the stem to metabolize cytokinins. In young leaves the contribution of isopentenyl adenine (iP)‐type cytokinins to the total cytokinin pool was about 50%, indicating that these leaves might be capable of de novo synthesis of cytokinins. In older leaves, the concentration of an unidentified cytokinin‐like compound increased to more than 50% of total cytokinins. This compound, which was also found in the roots, might be a storage form of cytokinins. In young axillary shoots, about 50% of the cytokinins are iP‐compounds, suggesting either import of iP‐type cytokinins via the phloem or de novo synthesis of cytokinins. In buds forming bottom breaks, ZR and zeatin riboside monophosphate (ZRMP) are the main cytokinins, indicating that these buds receive their cytokinins from the roots.
KW - Bud break
KW - cytokinins
KW - organ distribution
KW - Rosa hybrida
KW - rose
KW - translocation form
U2 - 10.1111/j.1399-3054.1997.tb00560.x
DO - 10.1111/j.1399-3054.1997.tb00560.x
M3 - Article
SN - 0031-9317
VL - 99
SP - 456
EP - 464
JO - Physiologia Plantarum
JF - Physiologia Plantarum
ER -