Constitutive overexpression of GmDof17-1, a putative DOF transcription factor from soybean causing growth inhibition in tobacco

The Dof proteins belong to a large family of plant transcription factors that share a single highly conserved zinc finger and play an important role in many physiological processes. To elucidate the function of Dof in soybean, GmDof17-1 was cloned from soybean (Glycine max (L.) Merr); the open reading frame (ORF) of GmDof17-1 is 846 bp and encodes a putative protein that includes 281 amino acids. Using qRT-PCR, the expression profiles of GmDof17-1 were obtained for various parts of the soybean plant. GmDof17-1 was primarily expressed in the roots and pods at various stages of pod development. The gene was ectopically expressed in tobacco under the control of the 2 × CaMV35S promoter to study the functions of the gene product. The transgenic tobacco plants showed to be dwarf, and the indole-3-acetic acid (IAA) content was decreased, whereas the sulfur-containing amino acid content of the seeds increased. These results provide new insight into the function of GmDof17-1 in seed development.

Constitutive overexpression of GmDof17-1, a putative DOF transcription factor from soybean causing growth inhibition in tobacco

The Dof proteins belong to a large family of plant transcription factors that share a single highly conserved zinc finger and play an important role in many physiological processes. To elucidate the function of Dof in soybean, GmDof17-1 was cloned from soybean (Glycine max (L.) Merr); the open reading frame (ORF) of GmDof17-1 is 846 bp and encodes a putative protein that includes 281 amino acids. Using qRT-PCR, the expression profiles of GmDof17-1 were obtained for various parts of the soybean plant. GmDof17-1 was primarily expressed in the roots and pods at various stages of pod development. The gene was ectopically expressed in tobacco under the control of the 2 × CaMV35S promoter to study the functions of the gene product. The transgenic tobacco plants showed to be dwarf, and the indole-3-acetic acid (IAA) content was decreased, whereas the sulfur-containing amino acid content of the seeds increased. These results provide new insight into the function of GmDof17-1 in seed development.(AU)

Orphan nuclear receptor regulation of reproduction

Orphan nuclear receptors, those without known ligands, were discovered because of their structural similarity to the ligand-driven steroid and thyroid receptors. Since their characterization, many of the orphan receptors have been adopted, i.e., ligands, usually lipids or derived lipids, have been discovered. The orphan receptors are transcriptional regulators, functioning in the reproductive context to upregulate or suppress gene expression. By this means, the orphan receptors regulate a plethora of reproductive events. In the majority of cases, the effects are stimulatory, indeed, members of the NR2 family promote Leydig cell differentiation and testicular steroidogenesis, while those of the NR4 family regulate early gestation and placental formation. The NR5 family has two members, steroidogenic factor-1 (SF-1, NR5A1) and liver receptor homolog-1 (LRH-1, NR5A2). These receptors interact with the same DNA sequence and are believed to be constitutive transcription factors. Their effects are modulated by the repressive effects of the NR0 family of orphan receptors that comprise the short heterodimeric partner (SHP, NR0B2) and dosage-sensitive sex reversal adrenal hypoplasia congenital region on the X chromosome, gene 1 (DAX1, NROB1). SHP and DAX1 inhibit the interaction of LRH-1 and SF-1 with coactivators, thereby reducing their constitutive transcriptional effects. Overall, the orphan nuclear receptors are essential regulators of reproductive function in mammals.

Orphan nuclear receptor regulation of reproduction

Orphan nuclear receptors, those without known ligands, were discovered because of their structural similarity to the ligand-driven steroid and thyroid receptors. Since their characterization, many of the orphan receptors have been adopted, i.e., ligands, usually lipids or derived lipids, have been discovered. The orphan receptors are transcriptional regulators, functioning in the reproductive context to upregulate or suppress gene expression. By this means, the orphan receptors regulate a plethora of reproductive events. In the majority of cases, the effects are stimulatory, indeed, members of the NR2 family promote Leydig cell differentiation and testicular steroidogenesis, while those of the NR4 family regulate early gestation and placental formation. The NR5 family has two members, steroidogenic factor-1 (SF-1, NR5A1) and liver receptor homolog-1 (LRH-1, NR5A2). These receptors interact with the same DNA sequence and are believed to be constitutive transcription factors. Their effects are modulated by the repressive effects of the NR0 family of orphan receptors that comprise the short heterodimeric partner (SHP, NR0B2) and dosage-sensitive sex reversal adrenal hypoplasia congenital region on the X chromosome, gene 1 (DAX1, NROB1). SHP and DAX1 inhibit the interaction of LRH-1 and SF-1 with coactivators, thereby reducing their constitutive transcriptional effects. Overall, the orphan nuclear receptors are essential regulators of reproductive function in mammals.(AU)