Determining the transcriptional regulation pattern of PgTIP1 in transgenic Arabidopsis thaliana by constructing gene

The seed size, seed mass, and growth rate of transgenic Arabidopsis plants containing PgTIP1, a ginseng tonoplast aquaporin gene, are significantly higher than those of wild-type Arabidopsis plants. Whole genome expression and bioinformatics analysis, including analysis of co-expression networks and transcription factors (Tfscan), were used to determine the key genes that are activated after the expression of PgTIP1 and the transcription factors that play important roles in the regulation of the genes controlling growth of Arabidopsis thaliana seeds by using transgenic Arabidopsis plants containing PgTIP1. Differential gene analysis showed that transformation of exogenous PgTIP1 to Arabidopsis induced endogenous gene expression changes. Analysis of gene co-expression networks revealed 2 genes, PIP1 (plasma membrane aquaporin 1 gene) and RD26 (responsive to desiccation 26 gene; a NAC transcription factor), that were localized in the core of the networks. Analysis of the transcriptional regulation network of transgenic Arabidopsis plants containing PgTIP1 showed that PIP1 and RD26 were regulated via DNA binding with a finger domain on transcription factor 2 (Dof2). In this study, we demonstrated that Dof2 induces up-regulation of PIP1 and RD26 after transformation with PgTIP1. The results of this study provide a new means for conducting research into and controlling growth of Arabidopsis thaliana seeds.