An Intrinsic MicroRNA Timer Regulates Progressive Decline in Shoot Regenerative Capacity in Plants
An Intrinsic MicroRNA Timer Regulates Progressive Decline in Shoot Regenerative Capacity in Plants
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DOI：
10.1105/tpc.114.135186
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发表时间：
2015-02
期刊：
影响因子：
11.6
通讯作者：
Tian-Qi Zhang;Heng Lian;Hong-Bo Tang;K. Doležal;Chuan-Miao Zhou;Sha Yu;Juan-Hua Chen;Qi Chen
中科院分区：
文献类型：
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作者：
Tian-Qi Zhang;Heng Lian;Hong-Bo Tang;K. Doležal;Chuan-Miao Zhou;Sha Yu;Juan-Hua Chen;Qi Chen
年龄调节植物再生能力。植物细胞是全能的，能够从分化的器官再生。已经表明，两种植物激素，生长素和细胞分裂素，在这一过程中发挥关键作用。和动物一样，植物的再生能力也随着年龄的增长而下降，但这种现象的分子基础仍然难以捉摸。在这里，我们证明了年龄调节的microRNA，miR156，调节芽再生能力。随着植物老化，miR 156靶向的鳞状细胞启动子结合蛋白样（SPL）转录因子的逐渐增加导致芽再生能力的逐渐下降。在老植物中，SPL通过与B型拟南芥应答调节因子结合减弱细胞分裂素应答来降低芽再生能力，所述B型拟南芥应答调节因子编码细胞分裂素信号传导途径中的转录激活因子。因此，增加外源细胞分裂素的量可以弥补老植株再生能力的下降。因此，招聘年龄线索响应细胞分裂素有助于芽再生能力。
Age regulates plant regenerative capacity. Plant cells are totipotent and competent to regenerate from differentiated organs. It has been shown that two phytohormones, auxin and cytokinin, play critical roles within this process. As in animals, the regenerative capacity declines with age in plants, but the molecular basis for this phenomenon remains elusive. Here, we demonstrate that an age-regulated microRNA, miR156, regulates shoot regenerative capacity. As a plant ages, the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors leads to the progressive decline in shoot regenerative capacity. In old plants, SPL reduces shoot regenerative capacity by attenuating the cytokinin response through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs, which encode the transcriptional activators in the cytokinin signaling pathway. Consistently, the increased amount of exogenous cytokinin complements the reduced shoot regenerative capacity in old plants. Therefore, the recruitment of age cues in response to cytokinin contributes to shoot regenerative competence.