Modulation of Gene Expression in Isolated Nuclei by Auxin-Binding Proteins

The nuclei isolated from etiolated mung bean hypocotyls had high levels of transcriptional activity and the capacity to synthesize full-size rRNA. The addition of auxin-binding proteins (ABP-I and ABP-II) to the nuclei, in the presence of IAA, caused the initiation of RNA synthesis. Translation in vitro of poly(A)+RNA prepared from these nuclei revealed that the level of one specific translation product, in each case, increased when the nuclei were treated with either ABP-I or ABP-II in the presence of IAA. The levels of two peptides which had the same molecular weights and isoelectric points as these two specifically translated peptides were also increased in the translation products of poly(A)+RNA from IAA-treated or 2,4-D-treated sections of mung bean hypocotyls.