Further Functional Analysis Of GA-Related Transcription Factor NBF

The regulations of GA biosynthesis play a great role during plants development and environmental adaptation. Studies have provided that transcription factors play essential roles to regulate genetic expression, which conduct signal to target gene by directly combinating with DNA and control the expression of target gene by a serial of regulations. The new transcription factor NBF has been successfully cloned by Doctor Wang of CAAS from maize by yeast one-hybrid system, and it is the first report of transcription factor of GA biosynthesis-related in maize. Studying the function of transcription factor NBF will illustrate the core sequence of DNA cis element binding to NBF and reveal the interactional mechanisms between NBF and DNA binding to it and define the regulating reaction between NBF and GA. This study will establish foundation for producing. In this context, further functional analysis of NBF will be presented and the major conclusions are as follows: 1. By yeast one-hybrid system, we found that the core sequence of DNA cis element binding to NBF in yeast cell was GCCANNTGGC. 2. Northern Blotting experiments showed that NBF gene was expressed in transgenic Arabidopsis N36, N43 and N51. 3. The analysis of transgenic Arabidopsis N36, N43 and N51 by Angilent gene chip indicated that NBF regulated several genes such as gibberellin-related genes, myb family transcription factor-related genes and disease resistance protein-related genes. 4. We identified further the target genes regulated by NBF in transgenic Arabidopsis by RT-PCR. The experiment showed that NBF controlled positively 12S cruciferin seed storage protein-related gene in transgenic Arabidopsis N43 and NBF controlled positively CCHH finger protein 2-like protein-related gene while controlled negatively gibberellin-regulated proteins-related gene in transgenic Arabidopsis N36, N43 and N51. 5. Studing the promoters of CPS,KS,KO,GA20ox,GA2ox and GA3ox that related to GA biosynthesis, we found that the promoters of KO,GA20ox and GA3ox contained the sequence CCA(N)nTGG. However, to understand whether NBF regulated directly KO,GA20ox and GA3ox or not, it will be necessary to study further.