木质部细胞分化的程序  

Program of Xylem Cell Differentiation

作　　者：崔克明[1] 

机构地区：[1]北京大学生命科学学院,北京100871

出　　处：《西北植物学报》2006年第8期1735-1748,共14页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金资助项目(30530620)

摘　　要：本文主要对近十几年来有关木质部细胞分化研究中使用的实验系统及用这些系统所取得的重要进展作了评述.并以作者实验室的研究成果为基础,结合国内外研究进展,提出木质部细胞分化程序由参与细胞编程死亡(PCD)和次生壁构建的全部基因综合编制而成.以PCD过程各阶段的划分标准来看,木质部细胞分化中从IAA诱导形成层细胞平周分裂到细胞扩大前为PCD的起始阶段,其间包括死亡信号的发生、接受和传导,以及启始caspase(半胱氨酰基天门冬氨酸蛋白酶)类似物(例如caspase-8类似物)的活化;木质部母细胞的径向扩大为PCD的效应阶段,而效应caspase类似物(例如caspase-3类似物)活化DNase、DNA的片段化及次生细胞壁的构建和各种细胞器的解体则为PCD的清除降解阶段.至今还无法将DNase活化及其引起的DNA断裂过程与次生细胞壁构建过程分开.The paper mainly focuses on commenting on the experimental systems that have been adopted in the researches about xylem cell differentiation in the recent several decades and the research advances that have been made with these systems. Based on the research achievements made by the author＇s lab and combining with research advances concerned at home and abroad, the paper puts forward that the program of xylem cell differentiation be established by all the genes taking part in programmed cell death and secondary cell wall formation. In accordance with the classification criteria of programmed cell death at various stages,the initial phase of PCD begins upon IAA induction of cambium cells to multiple by periclinal division and ends before cell enlargement in xylem cell differentiation and it includes the occurrences, reception and transmission of death signals,activation of promotor caspase（cysteinyl aspartate proteases）analog（ for example,caspase-8 analogs） ,and the effective stage of PCD is the period in which xylem mother cells radially enlarge and the clearing and disintegrating stage of PCD is the period in which effective caspase analogs（ for example,caspase-3 analogs）activate DNase,DNA fragmentation,secondary cellwall formation and the disintegration of various organelles. By now,there have been no ways to distinguish DNase activation and DNA fragmentation resulting from the activation from secondary cell wall formation.

关 键 词：木质部细胞分化 细胞编程死亡 实验系统 次生细胞壁构建 

分 类 号：Q944.6[生物学—植物学]