Spíchal Lukáš
Laboratory of Growth Regulators, Institute of Experimental Botany AS CR & Palacký University, Olomouc, Czech Republic.
Methods Mol Biol. 2011;779:139-47. doi: 10.1007/978-1-61779-264-9_7.
Cytokinins, like other phytohormones, act in plants as signaling molecules at very low concentrations. The system that mediates between their chemical recognition and the responses that they induce requires a hormone receptor that, together with down-stream located elements, forms a signaling network, converting the signal into a specific response. Identification of the cytokinin-binding histidine kinases CRE1/AHK4, AHK3, and AHK2 as cytokinin receptors in Arabidopsis was an important milestone in the elucidation of cytokinin signal transduction pathways. Their molecular characterization through the use of transgenic E. coli strains revealed that a variety of cytokinin compounds may have signaling functions, but only with specific receptors. This indicates that differential ligand specificities of the receptors may be a mechanism to fine-tune the various cytokinin responses. This chapter describes the detailed protocol of a method employing transgenic E. coli which substantially contributes to our understanding of cytokinin perception, a crucial step in the cytokinin regulation of diverse plant growth and development processes.
细胞分裂素与其他植物激素一样，在植物中以极低浓度作为信号分子起作用。介导其化学识别与诱导反应之间的系统需要一种激素受体，该受体与位于下游的元件一起形成一个信号网络，将信号转化为特定反应。在拟南芥中鉴定出细胞分裂素结合组氨酸激酶CRE1/AHK4、AHK3和AHK2作为细胞分裂素受体，是阐明细胞分裂素信号转导途径的一个重要里程碑。通过使用转基因大肠杆菌菌株对它们进行分子表征表明，多种细胞分裂素化合物可能具有信号功能，但仅与特定受体结合。这表明受体的不同配体特异性可能是微调各种细胞分裂素反应的一种机制。本章描述了一种使用转基因大肠杆菌的方法的详细方案，该方法极大地有助于我们理解细胞分裂素感知，这是细胞分裂素调节多种植物生长和发育过程中的关键步骤。
