Overlapping and non-redundant functions of the Arabidopsis auxin response factors MONOPTEROS and NONPHOTOTROPIC HYPOCOTYL 4

Citations Over TimeTop 1% of 2004 papers

Abstract

Transcription factors of the auxin response factor (ARF) family have been implicated in auxin-dependent gene regulation, but little is known about the functions of individual ARFs in plants. Here, interaction assays, expression studies and combinations of multiple loss- and gain-of-function mutants were used to assess the roles of two ARFs, NONPHOTOTROPIC HYPOCOTYL 4 (NPH4/ARF7) and MONOPTEROS (MP/ARF5), in Arabidopsis development. Both MP and NPH4 interact strongly and selectively with themselves and with each other, and are expressed in vastly overlapping domains. We show that the regulatory properties of both genes are far more related than suggested by their single mutant phenotypes. NPH4 and MP are capable of controlling both axis formation in the embryo and auxin-dependent cell expansion. Interaction of MP and NPH4 in Arabidopsis plants is indicated by their joint requirement in a number of auxin responses and by synergistic effects associated with the co-overexpression of both genes. Finally, we demonstrate antagonistic interaction between ARF and Aux/IAA gene functions in Arabidopsis development. Overexpression of MP suppresses numerous defects associated with a gain-of-function mutation in BODENLOS (BDL)/IAA12. Together these results provide evidence for the biological relevance of ARF-ARF and ARF-Aux/IAA interaction in Arabidopsis plants and demonstrate that an individual ARF can act in both invariantly programmed pattern formation as well as in conditional responses to external signals.

Related Papers

• → Hormonal Interactions in the Control of Arabidopsis Hypocotyl Elongation(2000)192 cited
• → The Arabidopsis Mutant alh1 Illustrates a Cross Talk between Ethylene and Auxin(2003)96 cited
• → Effect of auxins and plant oligosaccharides on root formation and elongation growth of mung bean hypocotyls(2005)40 cited
• → The Elongation Response of Watermelon Hypocotyls to Indole-3-Acetic Acid: A Comparative Study of Excised Segments and Intact Plants(1988)16 cited
• 콩의 종자크기, 온도 및 GA처리가 하배축신장에 미치는 영향(1992)