ATMYB123和ATKOR1基因参与拟南芥根发育的调控

ATMYB123 and ATKOR1 Genes Involve in the Development of Roots in Arabidopsis thaliana

从拟南芥T-DNA插入突变体库中筛选到2个根发育相关基因ATMYB123和ATKOR1表达缺失的突变体atmyb123和atkor1,通过杂交构建这两个基因表达缺失的双突变体atmyb123/atkor1,以明确这两个基因在根发育中的作用。结果显示:(1)ATMYB123表达缺失突变体atmyb123植株地上部分发育减缓,种皮颜色变黄,而ATKOR1表达缺失突变体atkor1植株在这两方面与其野生型没有明显差异;两基因缺失均显著影响了拟南芥根的发育,根生长受到了严重抑制。(2)双突变体atmyb123/atkor1在植株形态和种皮颜色方面表现出单突变体AT-MYB123的特点,而其根长却介于两单突变体的中间。(3)进一步研究发现,培养基pH改变、NaCl处理、外源GA施用均没有改变突变体根生长趋势,显示这3种因素与两基因缺失突变引起的根发育抑制无关。研究表明,AT-MYB123和ATKOR1基因参与拟南芥根的发育调控,转录因子ATMYB123可能作为主调控因子参与ATKOR1对拟南芥根发育的调控。

Two Arabidopsis mutants atrnyb123 and atkorl were identified from the T-DNA insertion knock- out mutant lines SAIL_005260 and SAIL 2_Gll ,respectively,and then a double mutant atmyb123/atkorl was established by crossing method. The two mutants are lacking expression for ATMYB123 and ATKOR1 genes,respectively,which two were found to be tightly related to root development in Arabidopsis thali- ana. The results obtained here showed that lack of ATMY13123 gene in expression led to a slow growth of plant rosettes and a yellow skin of seeds in Arabidopsis,while lack of ATKOR1 gene in expression had no marked effects on these two factors. Any one of the two genes ATMYB123 and ATKOR1 knockout ex- tremely repressed the root development in Arabidopsis, especially the knockout of ATKOR1 gene, the mu- tant atkorl showed only one third of length of roots as compared to wild type （WT）. Interestingly, the double mutant atmybt23/atkorl exhibited the characteristics of the single mutant atmyb123 has in plant rosette morphology and seed skins but presented intermediated root length between the two single mu- tants. In addition,the growth trend of roots among the three mutants had no fundamental changes when theplants were cultivated under different pH, NaC1 treatments and GA concentration conditions, which imply that these three factors were not concerned in the root shortening event induced by lack of any one of AT- MYB123 or/and ATKOR1 proteins in A. thaliana. These results suggest that both ATMYBI23 and AT- KOR1 genes participate in the root development of Arabidopsis and a specific relationship in functions exist between the two proteins,ATMYB123 and ATKOR1. The transcription factor ATMYB123 might act as a major regulator of ATKOR1 protein for participating the control of root development in Arabidopsis.