Non-cell-autonomous control of vascular stem cell fate by a CLE peptide/receptor system
Non-cell-autonomous control of vascular stem cell fate by a CLE peptide/receptor system
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DOI：
10.1073/pnas.0808444105
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发表时间：
2008-09-30
影响因子：
11.1
通讯作者：
Fukuda, Hiroo
中科院分区：
文献类型：
--
作者：
Hirakawa, Yuki;Shinohara, Hidefumi;Fukuda, Hiroo
陆地植物进化出了由木质部和韧皮部组成的水和养分的长距离运输系统，这两者都是由包含原形成层和形成层的维管干细胞产生的。然而，人们对控制木质部-韧皮部模式的细胞通讯的分子机制知之甚少。在这里，我们发现十二肽（HEVHypSGHypNPISN；Hyp，4-羟脯氨酸）TDIF（气管元件分化抑制因子）从韧皮部分泌，并通过富含亮氨酸的重复受体样激酶（LRR-RLK）抑制血管干细胞向木质部细胞的分化。 TDIF 在体外特异性结合 LRR-RLK，称为 TDR（推定的 TDIF 受体），其表达仅限于原形成细胞。然而，对TDIF与特异性抗体的联合分析以及编码TDIF的两个基因的启动子的表达谱表明，TDIF主要在韧皮部及其邻近细胞中合成并分泌。 TDIF 能够促进原形成层细胞增殖，同时抑制木质部分化，这一观察结果表明，这种小肽充当韧皮部来源的非细胞自主信号，控制原形成层中干细胞的命运。我们的结果表明，我们发现了一种控制韧皮部-木质部串扰的细胞通信系统。
Land plants evolved a long-distance transport system of water and nutrients composed of the xylem and phloem, both of which are generated from the procambium- and cambium-comprising vascular stem cells. However, little is known about the molecular mechanism of cell communication governing xylem-phloem patterning. Here, we show that a dodecapeptide (HEVHypSGHypNPISN; Hyp, 4-hydroxyproline), TDIF (tracheary element differentiation inhibitory factor), is secreted from the phloem and suppresses the differentiation of vascular stem cells into xylem cells through a leucine-rich repeat receptor-like kinase (LRR-RLK). TDIF binds in vitro specifically to the LRR-RLK, designated TDR (putative TDIF receptor), whose expression is restricted to procambial cells. However, the combined analysis of TDIF with a specific antibody and the expression profiles of the promoters of two genes encoding TDIF revealed that TDIF is synthesized mainly in, and secreted from, the phloem and its neighboring cells. The observation that TDIF is capable of promoting proliferation of procambial cells while suppressing xylem differentiation suggests that this small peptide functions as a phloem-derived, non-cell-autonomous signal that controls stem cell fate in the procambium. Our results indicate that we have discovered a cell communication system governing phloem-xylem cross-talk.