An ethylene-responsive enhancer element is involved in the senescence-related expression of the carnation glutathione-S-transferase (GST1) gene.

Abstract

The increased production of ethylene during carnation petal senescence regulates the transcription of the GSTI gene encoding a subunit ofglutathione-S-transferase. We have investigated the molecular basis for this ethyleneresponsive transcription by examining the cis elements and trans-acting factors involved in the expression of the GSTI gene. Transient expression assays following delivery ofGSTI 5' flanking DNA fused to a P-glucuronidase reporter gene were used to functionally define sequences responsible for ethyleneresponsive expression. Deletion analysis of the 5' fanking sequences of GST1 identifted a single positive regulatory element of 197 bp between -667 and -470 necesary for ethylene-responsive expression. The sequences within this ethylene-responsive region were further localized to 126 bp between -596 and -470. The ethylene-responsive element (ERE) within this region conferred ethylene-regulated expression upon a mi l cauliflower mosaic virus-35S TATA-box promoter in an orientation-independent manner. Gel electrophoresis mobilityshift assays and DNase I footprinting were used to identify proteins that bind to sequences within the ERE. Nuclear proteins from carnation petals were shown to specifically interact with the 126-bp ERE and the presence and binding of these proteins were independent of ethylene or petal senescence. DNase I footprinting defined DNA sequences between -510 and -488 within the ERE specifically protected by bound protein. An 8-bp sequence (ATTTCAAA) within the protected region shares si ant homology with promoter sequences required for ethylene responsiveness from the tomato fruitripening E4 gene.

Involvement of Ethylene in Stress-Induced Expression of the TLC1.1 Retrotransposon from Lycopersicon chilense Dun.

“…As shown in Figure 6, this region includes a near consensus TATA-box between nucleotides 194 and 200 and, notoriously, two 57-bp tandem repeated sequences (TRS1 and TRS2), sharing a 95% identity, in positions 38 to 94 (TRS1) and 95 to 151 (TRS2), respectively. A sequence motif that matches with the socalled ERE box (Itzhaki et al, 1994) was found within Figure 3. Northern analysis of TLC1.1 transcription in leaves from L. chilense plants exposed to wounding stress.…”

“…This 8-bp element has been previously identified as an ethylene-responsive enhancer in the tomato E4 and carnation (Dianthus caryophyllus) GST1 genes, both responsive to ethylene. Footprinting analysis has indicated that this sequence corresponds to a specific transcription factor binding site (Montgomery et al, 1993;Itzhaki et al, 1994). The participation of these putative ERE boxes in the regulation of TLC1.1 expression was demonstrated through promoter mutation analyses.…”

ETHYLENE-INSENSITIVE3 Is a Senescence-Associated Gene That Accelerates Age-Dependent Leaf Senescence by Directly Repressing miR164 Transcription in Arabidopsis

“…We performed chromatin immunoprecipitation (ChIP) experiments using iE/qm plants to test this possibility. We chose three regions in the miR164A promoter containing putative EBSs (TACAT or TTCAAA) (Itzhaki et al, 1994;Konishi and Yanagisawa, 2008;Zhong et al, 2009;An et al, 2012) (Figure 6A). We found marked enrichment of EIN3 in these EBS regions, particularly the P2 site (TACAT), indicating that EIN3 binds to this region in vivo ( Figure 6B).…”

Molecular Biology of Ethylene, a Review

“…The mechanism of ethylene-regulated genes has unraveled by molecular characterization of the promoter regions of ripening-related genes and thereby an ethylene-responsive element containing 8 bp motifs (A (A/T) TTCAAA) has been identified (Montgomery et al, 1993 andItzhaki et al, 1994). Similarly, two ethylene regulated genes, E4 and ER69 have been identified (Zegzouti et al, 1999) and these both genes are involved also in methionine cycle, encoding methionine sulphoxide reductase protein and cobalamine-independent methionine synthase respectively (Montgomery et al, 1993 andZegzouti et al, 1999).…”