The ocs element in the soybean GH2/4 promoter is activated by both active and inactive auxin and salicylic acid analogues

Ulmasov, Tim; Hagen, Gretchen; Guilfoyle, Tom J.

doi:10.1007/bf00040688

Cited by 104 publications

(89 citation statements)

References 53 publications

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“…Chemical Cues That Induce Transcription through as-1 and TGA1a-as-1 type elements confer gene expression in response to the phytohormones auxin, SA, and MJ, whereas other plant hormones, including the cytokinin benzyl-aminopurine and abscisic acid, are inactive (5,9,20,27,31). In contrast to these results, we found that trans-activation by GAL4-TGA1a⌬bZIP or endogenous TGA factors was induced by either natural (i.e.…”

Section: Sequences That Flank the Bzip Domain Of Tga1a Confermentioning

confidence: 99%

“…It has been previously shown that as-1 and related elements confer transcription in response to biologically active and inactive analogs of auxin, suggesting that this response may involve chemical stress cues (8,20). To further investigate this possibility, we tested the ability of the biologically active auxin 2,4-D and its inactive analog 2,3-D to stimulate transcription from the Ϫ90-CAT reporter.…”

Section: Sequences That Flank the Bzip Domain Of Tga1a Confermentioning

confidence: 99%

“…In addition, TGA1a is a member of a large group of bZIP transcription factors, the activity of which in many cases is governed by cellular and environmental cues (17)(18)(19). To investigate functional properties of this tobacco factor, we employed a homologous transient transfection assay with protoplasts, an approach that has been previously used to characterize as-1-dependent transcription (20). By co-transfection and gain-offunction assays, we show here that trans-activation by TGA1a is stimulated by auxins and their analogs via chemical stress.…”

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Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Pascuzzi

Hamilton

Bodily

et al. 1998

Journal of Biological Chemistry

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The promoter element activation sequence-1 (as-1) confers tissue-specific and signal-responsive transcription in plants. Hormone and chemical stress cues are thought to activate as-1-dependent transcription through specific basic/leucine-zipper proteins, termed TGA factors, that bind this element. We report here that a highly conserved TGA factor of tobacco, TGA1a, can selectively activate transcription in response to micromolar concentrations of auxin hormones or their analogs. This induction is chemically specific, as a range of other compounds tested at similar concentrations had little or no effect. Auxin was found to augment the transactivation potential of TGA1a through carboxyl-terminal residues. The amino-terminal domain of TGA1a, by gain-of-function assays, was found to both constitutively activate transcription and maximize the response to auxin. Further evidence indicates that the trans-activation potential of this domain in TGA1a is repressed, under basal conditions, by carboxyl-terminal residues. Because TGA1a and endogenous TGA factors are stimulated by auxin only at concentrations that inhibited cell growth, this response is likely to involve chemical stress.The expression of nuclear genes in response to cellular and environmental cues is largely regulated by trans-acting factors and their cognate cis-elements. In plants, auxin hormones (e.g., indole-3-acetic acid) promote growth and affect a number of cellular processes. Auxins are believed to mediate at least some of their effect by enhancing the expression of specific genes through target cis-elements (1, 2). The prototype for one class of auxin-responsive element is activation sequence-1 (as-1), 1 which was first identified by Lam et al. (3) in the cauliflower mosaic virus (CaMV) 35 S promoter. Homologs of as-1 (e.g., ocs and nos), moreover, occur in the promoters of plant-transforming T-DNA genes of agrobacteria (4 -6). Apart from regulating these genes in plants, a broader role for as-1 elements has been suggested by their functional presence in plant glutathione S-transferase genes (7-9). For example, auxin-responsive expression of at least one member of the tobacco GST gene family, GNT35, is mediated by as-1 (8, 9). Unlike other auxin-responsive elements, as-1 requires physiologically high (i.e. micromolar) concentrations of auxins to activate transcription, suggesting that this response may involve chemical stress. This view is further supported by the observation that biologically inactive analogs of auxins are also strong inducers of as-1-dependent activity.Multiple TGA factors that bind selectively to as-1 and related motifs have been cloned from several plant species, and some or all of these factors are likely to mediate as-1-dependent transcription. Based on their amino acid homology, at least three subclasses of TGA factors occur in plants, with multiple members in each class. Heterodimerization between these factors may generate new combinations with potentially distinct functional properties (10). Posttranscriptional regulation ...

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Section: Sequences That Flank the Bzip Domain Of Tga1a Confermentioning

confidence: 99%

Section: Sequences That Flank the Bzip Domain Of Tga1a Confermentioning

confidence: 99%

mentioning

confidence: 99%

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Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Pascuzzi

Hamilton

Bodily

et al. 1998

Journal of Biological Chemistry

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“…Such motifs have been collectively referred to as ACGT elements (ACEs, Armstrong et al, 1992;Weisshaar et al, 1991). They have been associated with light regulation of expression of a number of genes encoding proteins associated with photosynthesis (Castresana et al, 1988;Donald and Cashmore, 1990;Giuliano et al, 1988;Meier and Gruissem, 1994) and other light-inducible processes such as flavonoid biosynthesis (Schulze-Lefert et al, 1989), with response to abscisic acid (Marcotte et al, 1989;Mundy et al, 1990;Oeda et al, 1991) auxin (Liu and Lam, 1994) wounding (Rosahl et al, 1986) salicylic acid (Qin et al, 1994;Ulmasov et al, 1994;Zhang and Singh, 1994) and anaerobiosis (DeLisle and Ferl, 1990), and with controlled expression of plant histone genes in relation to cell proliferation (Mikami et al, 1994, Osley, 1991Tabata et al, 1991;Tereda et al, 1993Tereda et al, , 1995Yang et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Two bZIP proteins from Antirrhinum flowers preferentially bind a hybrid C‐box/G‐box motif and help to define a new sub‐family of bZIP transcription factors

et al. 1998

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SummaryTwo genes encoding bZIP proteins are expressed in flowers of Antirrhinum majus, predominantly in vascular tissues, carpels and anthers. The sequences of cDNA clones encoding these proteins show them to belong to a distinct subfamily of bZIP proteins which also includes LIP19 from rice and MLIPI5 and OBF1 from maize. The sub-family is characterized by the inclusion of very small proteins consisting of essentially a basic domain and a long leucine zipper. Members also have a conserved upstream open reading frame (uORF) in their 5Ј leader sequences, implying a common mode of post-transcriptional control. In vitro, the Antirrhinum bZIP proteins preferentially bind to a novel hybrid C-box/G-box motif which is found in the promoters of some plant histone genes and of some nuclear-encoded genes with plastidial protein products. Expression of the bZIP proteins in transgenic tobacco under control of the CaMV 35S promoter supports the view that they can regulate expression of genes which contain the preferred target motif within their regulatory sequences, although both enhancement and repression of transcript levels of target genes were observed, indicating that the bZIP proteins probably interact with other factors to modulate transcription in different ways, as has been observed for the small MAF family of bZIP proteins in vertebrates.

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“…These type I11 GSTs are induced by numerous environmental stress conditions, including those arising from pathogen attack (Taylor et al, 1990), oxidative stress (Wingate et al, 1988;Levine et al, 1994;Tenhaken et al, 1995), and heavy metal toxicity (Czarnecka et al, 1988;Hagen et al, 1988;Wingate et al, 1988;Mauch and Dudler, 1993). The type I11 GSTs also play a role in the cellular response to both natural and synthetic auxins (Droog et al, 1993;Hahn and Strittmatter, 1994;Ulmasov et al, 1994Ulmasov et al, , 1995Droog, 1995;Droog et al, 1995). Bz2 encodes a type 111 GST and Bz2 Plant Physiol.…”

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confidence: 99%

Expression and RNA Splicing of the Maize Glutathione S-Transferase Bronze2 Gene Is Regulated by Cadmium and Other Stresses

1997

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The Bronze2 (Bz2) gene in maize (Zea mays) encodes a glutathione S-transferase that performs the last genetically defined step in anthocyanin biosynthesis-tagging anthocyanin precursors with glutathione, allowing for recognition and entry of anthocyanins into the vacuole. Here we show that Bz2 gene expression is highly induced by heavy metals such as cadmium. Treatment of maize seedlings with cadmium results in a 20-fold increase i n 822 message accumulation and a 50-fold increase in the presence of the unspliced, intron-containing transcript. The increase in message levels during cadmium stress appears to result, at least in part, from activation of an alternative mRNA start site approximately 200 nucleotides upstream of the normal start site; this site is not used in unstressed or heat-stressed tissues. The effect of cadmium on the RNA splicing of Bz2 seems to be specific: splicing of other introncontaining maize genes, including a maize actin gene under the control of the cadmium-inducible 822 promoter, is unaffected by cadmium stress. Conversely, 822 intron splicing is not affected by other stress conditions that induce Bz2 gene expression, such as abscisic acid, auxin, or cold stress. Surprisingly, the increase in Bz2 mRNA during cadmium stress does not result in an increase in Bz2 glutathione Stransferase activity. We propose that an alternative protein may be encoded by 822 that has a role during responses t o heavy metals.Specific enzymatic and regulatory roles have been assigned for most genes of the anthocyanin pathway in maize (Zea mays) as a result of genetic and biochemical analysis. Bz2 is one of the last structural genes required for the production of anthocyanin pigmentation in maize (Coe et al., 1988;Holton and Cornish, 1995). In bz2 mutants cytoplasmic synthesized anthocyanin precursors are unable to reach their final destination in the vacuole. This inappropriate cytoplasmic accumulation of the precursor pigment cyanidin-3-glucoside causes tissues to develop a bronze color as a result of oxidation and condensation reactions that are poorly understood (Stafford, 1990). These oxidized secondary metabolites in the cytoplasm of bz2 mutants are

show abstract

The ocs element in the soybean GH2/4 promoter is activated by both active and inactive auxin and salicylic acid analogues

Cited by 104 publications

References 53 publications

Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Two bZIP proteins from Antirrhinum flowers preferentially bind a hybrid C‐box/G‐box motif and help to define a new sub‐family of bZIP transcription factors

Expression and RNA Splicing of the Maize Glutathione S-Transferase Bronze2 Gene Is Regulated by Cadmium and Other Stresses

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