Phloem transdifferentiation from immature xylem cells during bark regeneration after girdling in Eucommia ulmoides Oliv.
Phloem transdifferentiation from immature xylem cells during bark regeneration after girdling in Eucommia ulmoides Oliv.
复制标题
杜仲环剥后树皮再生过程中未成熟木质部细胞的韧皮部转分化。
DOI：
10.1093/jxb/ern041
复制
发表时间：
2008-04-01
影响因子：
6.9
通讯作者：
Cui, Ke-Ming
中科院分区：
文献类型：
--
作者：
Pang, Yu;Zhang, Jing;Cui, Ke-Ming
杜仲（杜仲科）是一种中国传统药用植物，被用于大规模研究环剥后树皮再生过程中的韧皮部细胞分化。在此表明，在环剥后树皮再生过程中，在创伤形成层形成之前，再生组织中就出现了新的筛管分子，并且它们可能源于树干上残留的未成熟/正在分化的轴向木质部细胞的转分化。对水培枝条的测定显示，环剥会阻断蔗糖运输，直至新筛管分子形成，并且功能性筛管分子的再生不依赖于环剥区域外轴系统提供的物质，而在伤口表面施加外源吲哚乙酸（IAA）会加速筛管分子的分化。这些实验表明，在一定条件下，未成熟的木质部细胞可以转分化为韧皮部细胞，这意味着木质部和韧皮部细胞在其分化途径的起始阶段可能具有一些相同的特征。这项研究还表明，树皮再生系统可以为研究木质部和韧皮部细胞分化提供一种新方法。
Eucommia ulmoides Oliv. (Eucommiaceae), a traditional Chinese medicinal plant, was used to study phloem cell differentiation during bark regeneration after girdling on a large scale. Here it is shown that new sieve elements (SEs) appeared in the regenerated tissues before the formation of wound cambium during bark regeneration after girdling, and they could originate from the transdifferentiation of immature/differentiating axial xylem cells left on the trunk. Assays of water-cultured twigs revealed that girdling blocked sucrose transport until the formation of new SEs, and the regeneration of the functional SEs was not dependent on the substance provided by the axis system outside the girdled areas, while exogenous indole acetic acid (IAA) applied on the wound surface accelerated SE differentiation. The experiments suggest that the immature xylem cells can transdifferentiate into phloem cells under certain conditions, which means xylem and phloem cells might share some identical features at the beginning of their differentiation pathway. This study also showed that the bark regeneration system could provide a novel method for studying xylem and phloem cell differentiation.