Ye Zheng-Hua, Freshour Glenn, Hahn Michael G, Burk David H, Zhong Ruiqin
Department of Plant Biology, University of Georgia, Athens 30602, USA.
Int Rev Cytol. 2002;220:225-56. doi: 10.1016/s0074-7696(02)20007-8.
Vascular tissues, xylem and phloem, form a continuous network throughout the plant body for transport of water, minerals, and food. Characterization of Arabidopsis mutants defective in various aspects of vascular formation has demonstrated that Arabidopsis is an ideal system for investigating the molecular mechanisms controlling vascular development. The processes affected in these mutants include initiation or division of procambium or vascular cambium, formation of continuous vascular cell files, differentiation of procambium or vascular cambium into vascular tissues, cell elongation, patterned secondary wall thickening, and biosynthesis of secondary walls. Identification of the genes affected by some of these mutations has revealed essential roles in vascular development for a cytokinin receptor and several factors mediating auxin transport or signaling. Mutational studies have also identified a number of Arabidopsis mutants defective in leaf venation pattern or vascular tissue organization in stems. Genetic evidence suggests that the vascular tissue organization is regulated by the same positional information that determines organ polarity.
维管组织，即木质部和韧皮部，在整个植物体内形成一个连续的网络，用于运输水分、矿物质和养分。对拟南芥中维管形成各个方面存在缺陷的突变体的表征表明，拟南芥是研究控制维管发育分子机制的理想系统。这些突变体中受影响的过程包括原形成层或维管形成层的起始或分裂、连续维管细胞列的形成、原形成层或维管形成层分化为维管组织、细胞伸长、有模式的次生壁加厚以及次生壁的生物合成。对其中一些突变影响的基因的鉴定揭示了细胞分裂素受体以及几种介导生长素运输或信号传导的因子在维管发育中的重要作用。突变研究还鉴定出了许多在叶脉模式或茎中维管组织组织方面存在缺陷的拟南芥突变体。遗传证据表明，维管组织的组织受决定器官极性的相同位置信息调控。
