Nitrate-specific and cytokinin-mediated nitrogen signaling pathways in plants.
Inorganic nitrogen is a limiting factor in plant growth and development. Plants constantly sense changes in nitrogen availability and respond appropriately by modulating gene expression. Plants employ multiple routes for the long-distance signaling and communication of nitrogen status. One of these depends on nitrate itself (nitrate-specific signaling), while another uses cytokinin as a messenger. Recent studies suggest that nitrate-specific signaling functions predominantly in the context of the synthesis of amino acids and nucleic acids. This pathway includes the control of the expression of a wide variety of genes. On the other hand, cytokinin-mediated signaling is related mainly to the control of nitrogen partitioning and development. Nitrogen-dependent cytokinin accumulation and the involvement of His-Asp phosphorelay systems are characteristic of this pathway. The coordination of both regulatory pathways seems to be crucially important for the integration of nitrogen signals at the whole plant level.
Sakakibara
Hitoshi
H
Plant Science Center, RIKEN (The Institute of Physical and Chemical Research), 1-7-22 Suehiro, Tsurumi, Yokohama 230-0045, Japan. sakaki@postman.riken.go.jp
D003583:Cytokinins / Q000378:metabolism*; D000071677:Histidine Kinase; D019684:Magnoliopsida / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction
D003583:Cytokinins; D009566:Nitrates; D010937:Plant Growth Regulators; D011494:Protein Kinases; D000071677:Histidine Kinase; D009584:Nitrogen