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The Amy32b gene is a representative member of a closely related family of alpha-amylase genes expressed under hormonal control in aleurone layers of barley grains. Transcription of this gene is induced by gibberellin (GA) and suppressed by abscisic acid. In this study, we functionally defined the promoter elements of the Amy32b gene that govern the(More)
The ripening-impaired tomato mutant Never-ripe (Nr) is insensitive to the plant hormone ethylene. The gene that cosegregates with the Nr locus encodes a protein with homology to the Arabidopsis ethylene receptor ETR1 but is lacking the response regulator domain found in ETR1 and related prokaryotic two-component signal transducers. A single amino acid(More)
Ethylene (C2H4) is a gaseous hormone that affects many aspects of plant growth and development. Ethylene perception requires specific receptors and a signal transduction pathway to coordinate downstream responses. The etr1-1 gene of Arabidopsis encodes a mutated receptor that confers dominant ethylene insensitivity. Evidence is presented here that etr1-1(More)
Seedlings of tomato fruit ripening mutants were screened for their ability to respond to ethylene. Ethylene induced the triple response in etiolated hypocotyls of all tomato ripening mutants tested except for one, Never ripe (Nr). Our results indicated that the lack of ripening in this mutant is caused by ethylene insensitivity. Segregation analysis(More)
In barley (Hordeum vulgare L. cv. Herta), slender (sln1) is a single-locus recessive mutation which causes a plant to appear as if it had been grown in sturating concentrations of gibberellin (GA). We have investigated two of the GA-mediated processes in slender barley, shoot elongation and the induction of hydrolytic enzymes in aleurone layers. Shoot(More)
Mutations in the ETR1 gene of the higher plant Arabidopsis confer insensitivity to ethylene, indicating a role for the gene product in ethylene signal perception and transduction. The ETR1 gene product has an amino-terminal hydrophobic domain and a carboxyl-terminal domain showing homology to the two-component signal transduction proteins of bacteria. We(More)
Fruit ripening represents a complex system of genetic and hormonal regulation of eukaryotic development unique to plants. We are using tomato ripening mutants as tools to elucidate genetic components of ripening regulation and have recently demonstrated that the Never-ripe (Nr) mutant is insensitive to the plant growth regulator ethylene (M.B. Lanahan,(More)
Fruit ripening is a complex developmental process that involves specific changes in gene expression and cellular metabolism. In climateric fruits these events are coordinated by the gaseous hormone ethylene, which is synthesized autocatalytically in the early stages of ripening. Nonclimacteric fruits do not synthesize or respond to ethylene in this manner,(More)
In cereal alpha-amylase gene promoters the cis-acting gibberellin response element (GARE) is required for increased transcription in the presence of gibberellin. In low-isoelectric point (pI) alpha-amylase gene promoters a second type of cis element, termed a coupling element, must also be present in a specific position near the GARE; otherwise, the level(More)
The promoters of a majority of cereal alpha-amylase genes contain three highly conserved sequences (gibberellin response element, box I, and pyrimidine box). Recent studies have demonstrated the functional importance of four regions that either coincide with or are immediately proximal to these three conserved elements as well as an upstream Opaque-2(More)