A proteoglycan mediates inductive interaction during plant vascular development
A proteoglycan mediates inductive interaction during plant vascular development
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DOI：
10.1038/nature02613
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发表时间：
2004-06-24
期刊：
影响因子：
64.8
通讯作者：
Fukuda, H
中科院分区：
文献类型：
--
作者：
Motose, H;Sugiyama, M;Fukuda, H
诱导性细胞间相互作用对于控制植物和动物的细胞命运决定至关重要（1）;然而，植物中诱导信号的化学基础仍然知之甚少。一种名为木质素的蛋白聚糖样因子介导了体外培养的百日菊细胞中木质部分化所需的局部和诱导性细胞-细胞相互作用（2，）3。本文描述了木质素的纯化及其互补DNA的克隆，并为木质素在植物中的作用提供了证据。木质素的多肽骨架是具有阿拉伯半乳聚糖蛋白和非特异性脂质转移蛋白性质的混合型分子。木质素主要积累在分生组织、原形成层和木质部中。在木质部中，木质素在分化中的导管分子的细胞壁中具有极性定位。双基因敲除拟南芥缺乏两个基因编码的木质素蛋白显示缺陷的血管发育：不连续的静脉，不正确的相互连接的导管元件和简化的脉序。我们的研究结果表明，木质素的极性分泌吸引邻近细胞进入维管分化的途径，以指导连续的维管发育，从而确定一种分子介导的诱导细胞参与植物组织分化的细胞相互作用。
Inductive cell-cell interactions are essential for controlling cell fate determination in both plants and animals(1); however, the chemical basis of inductive signals in plants remains little understood. A proteoglycan-like factor named xylogen mediates local and inductive cell-cell interactions required for xylem differentiation in Zinnia cells cultured in vitro(2,)3. Here we describe the purification of xylogen and cloning of its complementary DNA, and present evidence for its role in planta. The polypeptide backbone of xylogen is a hybrid-type molecule with properties of both arabinogalactan proteins and nonspecific lipid-transfer proteins. Xylogen predominantly accumulates in the meristem, procambium and xylem. In the xylem, xylogen has a polar localization in the cell walls of differentiating tracheary elements. Double knockouts of Arabidopsis lacking both genes that encode xylogen proteins show defects in vascular development: discontinuous veins, improperly interconnected vessel elements and simplified venation. Our results suggest that the polar secretion of xylogen draws neighbouring cells into the pathway of vascular differentiation to direct continuous vascular development, thereby identifying a molecule that mediates an inductive cell cell interaction involved in plant tissue differentiation.