Involvement of Arabidopsis Histone Acetyltransferase HAC Family Genes in the Ethylene Signaling Pathway

Li, Chao
Xu, Jiang
Li, Jian
Li, Qingyun
Yang, Hongchun

¹Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
²National Institute of Biological Sciences, Beijing, 102206 China
³Department of Molecular Biology and Biochemistry, Lederle Graduate Research Tower, University of Massachusetts, Amherst, MA 01003, USA
⁴These authors contributed equally to this work.

*Corresponding author: E-mail, [email protected]; Fax, 413-545-3291

Received August 5, 2013

Accepted November 24, 2013

Plant and Cell Physiology 55(2):p 426-435, February 2014. | DOI: 10.1093/pcp/pct180

Epigenetic modifications play a fundamental role in regulating chromatin dynamics and gene expression. The level of histone acetylation is controlled by two functionally antagonistic enzymes, namely histone acetyltransferase (HAT) and histone deacetylase (HDAC). CREB-binding protein (CBP)/p300 proteins, a subfamily of highly conserved HATs, are involved in various physiological events including proliferation, differentiation and apoptosis. In this work, we study the poorly known function of their homologous genes, the HAC genes, in Arabidopsis. We found that hac1-involved mutants displayed pleiotropic phenotypes, in particular hypersensitivity to ethylene both in the dark and in the light. We also found that the transcriptional levels of ethylene-responsive genes are significantly higher in the hac1hac5 double mutant than in wild-type plants. Moreover, an ethylene synthesis inhibitor cannot release the triple responses of hac mutants. These results suggest that HACs are involved in the ethylene signaling pathway.