Polarity, Continuity, and Alignment in Plant Vascular Strands

作     者：Megan G.Sawchuk Enrico Scarpella 

作者机构：Department of Biological Sciences University of AlbertaEdmonton Alberta Canada T6G 2E9 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2013年第55卷第9期

页      面：824-834页

核心收录：

学科分类：0710[理学-生物学] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 0703[理学-化学] 0902[农学-园艺学] 

基　　金：supported by Discovery Grants of the Natural Sciences and Engineering Research Council of Canada (NSERC) M.G.S. was supported by an NSERC CGS‐M Scholarship and an NSERC CGS‐D Scholarship 

主　　题：Auxin transport callus tissue embryo axis leaf vein vascular network. 

摘      要：Plant vascular cells are joined end to end along uninterrupted lines to connect shoot organs with roots;vascular strands are thus polar, continuous, and internally aligned. What controls the formation of vascular strands with these properties？ The “auxin canalization hypothesis-based on positive feedback between auxin flow through a cell and the cell’s capacity for auxin transport-predicts the selection of continuous files of cells that transport auxin polarly, thus accounting for the polarity and continuity of vascular strands. By contrast, polar, continuous auxin transport-though required-is insufficient to promote internal alignment of vascular strands, implicating additional factors. The auxin canalization hypothesis was derived from the response of mature tissue to auxin application but is consistent with molecular and cellular events in embryo axis formation and shoot organ development. Objections to the hypothesis have been raised based on vascular organizations in callus tissue and shoot organs but seem unsupported by available evidence. Other objections call instead for further research; yet the inductive and orienting influence of auxin on continuous vascular differentiation remains unique.