Involvement of Arabidopsis HAC family genes in pleiotropic developmental processes.

With intrinsic acetyltransferase activities, CREB binding protein (CBP)/p300 proteins mediate a variety of physiological events, such as proliferation, differentiation, and apoptosis, by regulating both histones and non-histone proteins. Arabidopsis CBP-type histone acetyltransferase family proteins, HACs, have been found to influence flower by regulating the expression of Flowering Locus C. We recently reported that HAC family genes involved in the ethylene signaling pathway. Thereafter, we systematically analyzed the morphological and developmental phenotypes of all the hac mutant combinations including plant size, root, flower, leaf defects, and late-flowering. Here we reinforce the ubiquitous regulation mechanism of HAC family genes, in which HAC1 plays a dominant role with the synergistic assist of HAC5 and HAC12, but HAC4 slightly alleviates the influence of HAC1 and HAC5.