Involvement of hormone signaling and transcription factors in the tissue-reunion process of Arabidopsis cut flowering stem.

Abstract

Our previous works showed that cell division starts at 3 days after cutting, and tissue-reunion almost completes in 7days in Arabidopsis cut flowering stems and microarray analysis revealed that genes determined to be up-regulated at earlier stage include those that are related to phytohormone signaling and transcription factors (TF). In this study, we performed molecular analysis for tissue-reunion process. Auxin-responsible IAA gene was significantly up-regulated at 1day after cutting and mIAA transgenic plants, of which auxin response were suppressed, showed lower efficiency in the reunion process. ACC synthase and putative ethylene-responsive AP2-TF showed similar expression patterns. Ethylene-signaling deficient mutant also showed lower efficiency, and knockout plants for AP2-TF or NAC-TF using CRES-T methods did not show normal reunion process. These results suggest that auxin /ethylene signaling pathways and putative downstream TFs have an important role in the regulation of gene expression during tissue-reunion of Arabidopsis cut flowering stems.