Cytokinin signalling regulates two-stage inflorescence arrest in Arabidopsis
Cytokinin signalling regulates two-stage inflorescence arrest in Arabidopsis
复制标题
细胞分裂素信号调节拟南芥两阶段花序停滞
DOI：
10.1101/2022.01.06.475268
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Walker C
中科院分区：
文献类型：
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作者：
Walker C
为了最大限度地获得繁殖成功，开花植物必须正确地确定进入和退出生殖阶段的时间。虽然调控开花的机制已知很多，但花的末期仍在很大程度上没有特征。拟南芥(Arabitopsis Thaliana)的开花末期由花序的准同步停滞组成，但关于环境刺激和生殖成功的停滞是如何正确地进行的尚不清楚。在这里，我们发现拟南芥花序停滞是一种复杂的发育现象，它包括花序分生组织(IM)的停滞，以及所有未打开的花原基的可分离的“花停滞”；这些事件发生在可见的花序停滞之前。我们发现，整体花序去除延迟IM和花的停滞，但局部果实的去除只延迟花的停滞，强调它们的分离性。我们测试了细胞分裂素是否调节花序停滞，发现细胞分裂素信号动力学反映了IM的活性，而细胞分裂素处理可以延缓IM和花的停滞。我们进一步证明，获得功能的细胞分裂素受体突变体可以延缓IM和花的停滞；相反，功能缺失的突变体阻止了开花延长对花序移除的响应。综上所述，我们的数据表明，细胞分裂素在越来越多的汇聚器官中的稀释通过触发IM和花的停止而导致拟南芥的花的末期。
To maximize reproductive success, flowering plants must correctly time entry and exit from the reproductive phase. While much is known about mechanisms that regulate initiation of flowering, end-of-flowering remains largely uncharacterized. End-of-flowering in Arabidopsis (Arabidopsis thaliana) consists of quasi-synchronous arrest of inflorescences, but it is unclear how arrest is correctly timed with respect to environmental stimuli and reproductive success. Here, we showed that Arabidopsis inflorescence arrest is a complex developmental phenomenon, which includes the arrest of the inflorescence meristem (IM), coupled with a separable “floral arrest” of all unopened floral primordia; these events occur well before visible inflorescence arrest. We showed that global inflorescence removal delays both IM and floral arrest, but that local fruit removal only delays floral arrest, emphasizing their separability. We tested whether cytokinin regulates inflorescence arrest, and found that cytokinin signaling dynamics mirror IM activity, while cytokinin treatment can delay both IM and floral arrest. We further showed that gain-of-function cytokinin receptor mutants can delay IM and floral arrest; conversely, loss-of-function mutants prevented the extension of flowering in response to inflorescence removal. Collectively, our data suggest that the dilution of cytokinin among an increasing number of sink organs leads to end-of-flowering in Arabidopsis by triggering IM and floral arrest.