Involvement of gibberellin and its correlation with CLE peptides in Arabidopsis development

Abstract

GA-deficient mutant of Arabidopsis thaliana was used to observe the effect of GA in root growth and development. In order to find out whether gene expression in the root is affected by GA4 applied to the shoot, microarray analysis was performed using root samples of GA-treated plant. The results allowed us to select several up- and down-regulated genes. The selected up-regulated genes included members of the CLE gene family, which encode precursors for secreted small peptides, collectively called CLE peptides. This discovery led us to speculate that GA-responsive CLE genes might play an important role in long distance signaling between shoots and roots and its interaction with GA. To elucidate the role of these CLE genes, we generated transgenic Arabidopsis plants that over-express or under-express CLE genes. Also Tissue-specific expression of CLE gene was observed in stele and branching points of root. This new finding has provided an opportunity to investigate further the existing relationships between CLE peptides and GA and their role in plant development.