A 1050 bp up-stream regulatory fragment of the transcription factor gene NAC1in Arabidopsis thaliana was isolated using polymerase chain reaction (PCR) based techniques. Thefragment was used to substitute the 35S promoter of the pBI121 plasmid to construct abate-glucuronidase gene (GUS) expression system. The construct was introduced into tobacco(Nico-tiana tabaccum) plants by the Agrobacterium-med\aled transferring method. GUS expressionpattern was studied by using the transgenic lines. The results showed that the GUS driven by theNAC1 up-stream regulatory region was specifically expressed in the root meristem region, basal areasof the lateral root primordium and the lateral roots. The GUS expression was induced by3-indolebutyric acid (IBA)and gibberellins (GA_3 and GA_(4+7)). The results indicated that theup-stream regulatory fragment of NAC1 responded to plant hormones. The fragment might be involved inboth auxins and gibberellins signaling in promoting the development of lateral roots.
WANG Youhua 1 ,DUAN Liusheng 1 ,LU Mengzhu 2 ,LI Zhaohu 1 ,WANG Minjie 2 &ZHAI Zhixi 1 1.State Key Laboratory of Plant Physiology and Biochemistry,Department of Agronomy,College of Agronomy and Biotech- nology,China Agricultural University,Beijing 100094,China
