LBD29基因在拟南芥侧根发生过程中的作用

Role of LBD29 gene in lateral root initiation of Arabidopsis thaliana

以拟南芥LBD29基因功能缺失突变体lbd29为材料,采用显微及亚显微技术,研究了拟南芥LBD29基因对于中柱鞘细胞分化和侧根发生的影响。结果显示:(1)与野生型相比,lbd29侧根发生晚,侧根数量少;(2)拟南芥根成熟区中柱鞘细胞是由两类分化程度不同的细胞组成,侧根原基形成前,位于木质部极中柱鞘的侧根原基建成细胞(founder cells)首先经历了脱分化,进而分裂形成侧根原基;(3)突变体中柱鞘细胞生长素响应不敏感,具有一定程度的脱分化障碍。以上结果初步表明,LBD29基因可能通过生长素响应通路调控中柱鞘founder cells的脱分化及分裂,从而影响侧根发生。

The effect of LBD29 gene on diffentiation of pericycle cells and lateral root initiation in Arabidopsis thaliana were investigated using microscopy and electron microscopy.The results showed that：（1）compared with wild-type of Arabidopsis thaliana,lbd29 forms fewer lateral roots in a later period;（2）the pericycle cells in maturation zone of root tip consist of two types of cells in differentiation degree and the pericycle founder cells at xylem pole divide to form lateral root primordium after dedifferentiation;（3）lbd29 pericycle cells are too insensitive to ectohormone to dedifferentiate.Thus,LBD29 may affect lateral root initiation by regulating dedifferentiation and division via auxin response pathway.