Regulation of cytokinin biosynthesis, compartmentalization and translocation

Cytokinins, a group of mobile phytohormones, play an important role in plant growth and development, and their activity is finely controlled by environmental factors in the control of morphogenic and metabolic adaptations. Inorganic nitrogen sources, such as nitrate, are a major factor regulating ge...

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Veröffentlicht in:Journal of experimental botany. - 1985. - 59(2008), 1 vom: 01., Seite 75-83
1. Verfasser: Hirose, Naoya (VerfasserIn)
Weitere Verfasser: Takei, Kentaro, Kuroha, Takeshi, Kamada-Nobusada, Tomoe, Hayashi, Hiroaki, Sakakibara, Hitoshi
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2008
Zugriff auf das übergeordnete Werk:Journal of experimental botany
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Review Cytokinins Ligands Alkyl and Aryl Transferases EC 2.5.- adenylate isopentenyltransferase EC 2.5.1.27
Beschreibung
Zusammenfassung:Cytokinins, a group of mobile phytohormones, play an important role in plant growth and development, and their activity is finely controlled by environmental factors in the control of morphogenic and metabolic adaptations. Inorganic nitrogen sources, such as nitrate, are a major factor regulating gene expression of adenosine phosphate-isopentenyltransferase (IPT), a key enzyme of cytokinin biosynthesis. Modulation of IPT and macronutrient transporter gene expression in response to nitrate, sulphate and phosphate, and cytokinin-dependent repression of the transporter genes suggest that cytokinins play a critical role in balancing acquisition and distribution of macronutrients. Biased distribution of trans-zeatin (tZ)-type cytokinins in xylem and N(6)-(Delta(2)-isopentenyl)adenine (iP)-type cytokinins in phloem saps suggest that, in addition to acting as local signals, cytokinins communicate acropetal and systemic long-distance signals, and that structural side chain variations mediate different biological messages. The compartmentalization of tZ- and iP-type cytokinins implies the involvement of a selective transport system. Recent studies have raised the possibility of subsets of the purine permease family as a transporter of cytokinin nucleobases and equilibrative nucleoside transporters (ENT) for cytokinin nucleosides. These biochemical and transgenic data suggest that AtENT6, an Arabidopsis ENT, could also participate in cytokinin nucleoside transport with a preference for iP riboside in vascular tissue
Beschreibung:Date Completed 30.04.2008
Date Revised 10.03.2022
published: Print-Electronic
Citation Status MEDLINE
ISSN:1460-2431