| Abstrakt: |
Cytokinins influence many aspects of plant growth and development, including apical dominance, leaf expansion and senescence, nutrient mobilization, chloroplast differentiation and activation of shoot meristems (22). This chapter1 seeks to provide an overview of what is currently known about the signaling mechanisms underlying these cytokinin effects. The biosynthesis, transport, metabolism and specific biological action of cytokinins is covered elsewhere in this book. Over the past ten years many advances have been made toward the understanding of cytokinin signaling including the cloning of several cytokinin receptors and their potential downstream effectors. The primary cytokinin signaling mechanism appears to be analogous to bacterial two-component phosphorelay systems that sense and respond to environmental signals. However, additional pathways may exist and other distinct signaling components have also been implicated in the cytokinin primary response. This chapter will focus on the evidence for early cytokinin signaling events that are similar to the two-component phosphorelay model. In addition, we present summaries of the signaling links between cytokinin and meristem activation and an overview of other genes potentially involved in cytokinin signaling. [ABSTRACT FROM AUTHOR] |
