Reduced ethylene synthesis by transgenic tomatoes expressing S-adenosylmethionine hydrolase

• Published in: Plant molecular biology Vol. 26; no. 3; p. 781
• Main Authors: Good, X. (Agritope Inc., Beaverton, OR (USA)), Kellogg, J.A, Wagoner, W, Langhoff, D, Matsumura, W, Bestwick, R.K
• Format: Journal Article
• Language: English
• Published: Netherlands 01.11.1994
• Subjects: Bacteriophage T3 - enzymology; Bacteriophage T3 - genetics; Base Sequence; ETHYLENE; Ethylenes - biosynthesis; ETILENO; EXPRESION GENICA; EXPRESSION DES GENES; GENE EXPRESSION; Gene Expression Regulation; Genetic Vectors; Hydrolases - biosynthesis; Hydrolases - genetics; LYCOPERSICON ESCULENTUM; Lycopersicon esculentum - genetics; Lycopersicon esculentum - growth & development; Lycopersicon esculentum - metabolism; MADURAMIENTO; METHIONINE; METIONINA; Molecular Sequence Data; MURISSAGE; Plant Growth Regulators - metabolism; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants, Genetically Modified - metabolism; Promoter Regions, Genetic - genetics; Recombinant Fusion Proteins - biosynthesis; Rhizobium - genetics; RIPENING; Transformation, Genetic; TRANSGENIC PLANTS
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/BF00028848

We have utilized a gene from bacteriophage T3 that encodes the enzyme S-adenosylmethionine hydrolase (SAMase) to generate transgenic tomato plants that produce fruit with a reduced capacity to synthesize ethylene. S-adenosylmethionine (SAM) is the metabolic precursor of 1-aminocyclopropane-1-carboxylic acid, the proximal precursor to ethylene. SAMase catalyzes the conversion of SAM to methylthioadenosine and homoserine. To restrict the presence of SAMase to ripening fruit, the promoter from the tomato E8 gene was used to regulate SAMase gene expression. Transgenic tomato plants containing the 1.1 kb E8 promoter bore fruit that expressed SAMase during the breaker and orange stage of fruit ripening and stopped expression after the fruit fully ripened. Plants containing the 2.3 kb E8 promoter expressed SAMase at higher levels during the post-breaker phases of fruit ripening and had a substantially reduced capacity to synthesize ethylene.