Laplaze Laurent, Parizot Boris, Baker Andrew, Ricaud Lilian, Martinière Alexandre, Auguy Florence, Franche Claudine, Nussaume Laurent, Bogusz Didier, Haseloff Jim
UMR 1098, Institut de Recherche pour le Développement, 911 Avenue Agropolis, F-34394 Montpellier cedex 5, France.
J Exp Bot. 2005 Sep;56(419):2433-42. doi: 10.1093/jxb/eri236. Epub 2005 Jul 25.
Lateral root development occurs throughout the life of the plant and is responsible for the plasticity of the root system. In Arabidopsis thaliana, lateral root founder cells originate from pericycle cells adjacent to xylem poles. In order to study the mechanisms of lateral root development, a population of Arabidopsis GAL4-GFP enhancer trap lines were screened and two lines were isolated with GAL4 expression in root xylem-pole pericycle cells (J0121), i.e. in cells competent to become lateral root founder cells, and in young lateral root primordia (J0192). These two enhancer trap lines are very useful tools with which to study the molecular and cellular bases of lateral root development using targeted gene expression. These lines were used for genetic ablation experiments by targeting the expression of a toxin-encoding gene. Moreover, the molecular bases of the enhancer trap expression pattern were characterized. These results suggest that the lateral-root-specific GAL4 expression pattern in J0192 is due to a strong enhancer in the promoter of the LOB-domain protein gene LBD16.
侧根发育贯穿植物的整个生命周期，并且决定了根系的可塑性。在拟南芥中，侧根起始细胞起源于与木质部极相邻的中柱鞘细胞。为了研究侧根发育的机制，对一批拟南芥GAL4-GFP增强子捕获系进行了筛选，分离出两个品系，其中一个品系（J0121）在根木质部极中柱鞘细胞（即有能力成为侧根起始细胞的细胞）以及幼嫩侧根原基中表达GAL4，另一个品系（J0192）也是如此。这两个增强子捕获系是非常有用的工具，可用于通过靶向基因表达来研究侧根发育的分子和细胞基础。通过靶向毒素编码基因的表达，利用这些品系进行了基因消融实验。此外，还对增强子捕获表达模式的分子基础进行了表征。这些结果表明，J0192中侧根特异性GAL4表达模式是由于LOB结构域蛋白基因LBD16启动子中的一个强增强子所致。
