Abstract
GH3 gene was firstly isolated from Glycine max as early auxin inducible gene. In Arabidopsis genome, GH3 gene family was consisted of 20 members of GH3 gene. One GH3 mutant, ydk1-D was isolated from activation tagged lines as dwarfed mutant, and this mutant showed short hypocotyls, epinastic leaves, short primary root and reduced number of lateral roots. The expression level of YDK1 gene was increased by exogenously applied auxin and this induction was mainly regulated by ARF7. Here, we will report histochemical analysis of YDK1 gene expression using YDK1 promoter-GUS reporter gene construct. Strong YDK1 promoter activity was detected in lateral root branches in GUS transgenic seedlings. Our results showed good correlation between expression patterns of YDK1 gene and root phenotype that was observed in ydk-D seedlings, suggesting YDK1 might function inhibition in primary root elongation. In addition, YDK1 gene expression was down-regulated by blue and far-red light irradiations.
