Zubo Yan O, Schaller G Eric
Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA.
Plants (Basel). 2020 Jan 30;9(2):166. doi: 10.3390/plants9020166.
Cytokinin is an important phytohormone that employs a multistep phosphorelay to transduce the signal from receptors to the nucleus, culminating in activation of type-B response regulators which function as transcription factors. Recent chromatin immunoprecipitation-sequencing (ChIP-seq) studies have identified targets of type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs) and integrated these into the cytokinin-activated transcriptional network. Primary targets of the type-B ARRs are enriched for genes involved in hormonal regulation, emphasizing the extensive crosstalk that can occur between cytokinin, auxin, abscisic acid, brassinosteroids, gibberellic acid, ethylene, jasmonic acid, and salicylic acid. Examination of hormone-related targets reveals multiple regulatory points including biosynthesis, degradation/inactivation, transport, and signal transduction. Here, we consider this early response to cytokinin in terms of the hormones involved, points of regulatory crosstalk, and physiological significance.
细胞分裂素是一种重要的植物激素，它利用多步磷酸化信号转导途径将信号从受体传递到细胞核，最终激活作为转录因子发挥作用的B型响应调节因子。最近的染色质免疫沉淀测序（ChIP-seq）研究已经确定了B型拟南芥响应调节因子（ARRs）的靶标，并将这些靶标整合到细胞分裂素激活的转录网络中。B型ARRs的主要靶标富含参与激素调节的基因，这强调了细胞分裂素、生长素、脱落酸、油菜素内酯、赤霉素、乙烯、茉莉酸和水杨酸之间可能发生的广泛串扰。对激素相关靶标的研究揭示了多个调控点，包括生物合成、降解/失活、运输和信号转导。在这里，我们从涉及的激素、调控串扰点和生理意义等方面来考虑对细胞分裂素的这种早期反应。
