Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Curr Opin Plant Biol. 2010 Dec;13(6):670-6. doi: 10.1016/j.pbi.2010.08.011. Epub 2010 Sep 23.
In vascular development, uncommitted cells differentiate into different xylem cells through vascular stem cells, such as procambial cells, during vein formation as well as embryogenesis. Cascades of transcriptional regulation of genes play crucial roles in the progress of vascular development. Auxin, cytokinin, and brassinosteroids also function in procambial cell determination, procambial maintenance, and xylem cell differentiation from procambial cells, respectively, through transcriptional regulation. The positive feedback loop typically shown in auxin-flow-MONOPTEROS-(HD-ZIP IIIs)-PIN1-auxin-flow in procambial precursor cell determination and VND7-ASL/LBD-VND7 in xylem vessel cell determination, may be a crucial mechanism that determines vascular cell fates, which occurs in stages.
在血管发育过程中，未分化的细胞通过血管干细胞（如原形成层细胞）分化为不同的木质部细胞，这一过程发生在叶脉形成和胚胎发生过程中。基因转录调控级联在血管发育过程中起着至关重要的作用。生长素、细胞分裂素和油菜素内酯分别通过转录调控作用于原形成层细胞的决定、原形成层的维持以及原形成层细胞向木质部细胞的分化。在原形成层前体细胞决定和木质部导管细胞决定中，生长素流-MONOPTEROS-(HD-ZIP IIIs)-PIN1-生长素流的正反馈环，可能是一个关键的机制，决定了血管细胞的命运，这个过程是分阶段进行的。
