Aux/IAA proteins repress expression of reporter genes containing natural and highly active synthetic auxin response elements.

Abstract

A highly active synthetic auxin response element (AuxRE), referred to as DR5, was created by performing site-directed mutations in a natural composite AuxRE found in the soybean GH3 promoter. DR5 consisted of tandem direct repeats of 11 bp that included the auxin-responsive TGTCTC element. The DR5 AuxRE showed greater auxin responsiveness than a natural composite AuxRE and the GH3 promoter when assayed by transient expression in carrot protoplasts or in stably transformed Arabidopsis seedlings, and it provides a useful reporter gene for studying auxin-responsive transcription in wild-type plants and mutants. An auxin response transcription factor, ARF1, bound with specificity to the DR5 AuxRE in vitro and interacted with Aux/IAA proteins in a yeast two-hybrid system. Cotransfection experiments with natural and synthetic AuxRE reporter genes and effector genes encoding Aux/IAA proteins showed that overexpression of Aux/IAA proteins in carrot protoplasts resulted in specific repression of TGTCTC AuxRE reporter gene expression.

Light modulates the root tip excision induced lateral root formation in tomato

“…Several studies have indicated that activity of the synthetic consensus auxin reporter, DR5::GUS, closely reflects the auxin induced gene expression in plant tissues. 28,29 The root tips were excised at 4 DAG from DR5::GUS transgenic seedlings and roots were stained for GUS activity 24 h after excision, using a protocol described in Santisree et al 30 In root tip decapitated seedlings, DR5::GUS activity was localized in the pericycle region associated with the primordia of emerging lateral roots (Fig. 1).…”

Manipulation of Intracellular Auxin in a Single Cell by Light with Esterase‐Resistant Caged Auxins

“…[14] This DR5::GUS line carries the b-glucuronidase (GUS) reporter gene, which is under the control of an auxin-responsive DR5 promoter. This reporter line is highly sensitive and specific to biologically active auxins and the GUS reporter enzyme expression is tightly regulated by intracellular auxin in a dose-dependent manner.…”

“…The transgenic Arabidopsis reporter line DR5::GUS was previously described. [14] Suspension-cultured transgenic tobacco BY-2 cells, DR5::GFP and GFP-Talin lines [15,17] were maintained in modified MS medium (4.3 g L À1 Murashige and Skoog salts (Duchefa, Haarlem, The Netherlands), 30 g L À1 sucrose, 200 mg L À1 KH 2 PO 4 , 100 mg L À1 inositol, and 1 mg L À1 thiamine, pH 5.8) as described previously [18] on a rotary shaker (150 rpm) at 25 8C in the dark.…”

BEM46 Shows Eisosomal Localization and Association with Tryptophan-Derived Auxin Pathway in Neurospora crassa

“…Figure 8 shows data indicating auxin production in N. crassa, which had been observed previously as well (63). Transgenic Arabidopsis thaliana plants expressing the DR5::GUS fusion protein (37,64) were incubated either with water (Fig. 8A), with 100 M IAA (Fig.…”