Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato

• Published in: The Plant journal : for cell and molecular biology Vol. 41; no. 5; pp. 651 - 659
• Main Authors: O'Malley, R.C, Rodriguez, F.I, Esch, J.J, Binder, B.M, O'Donnell, P, Klee, H.J, Bleecker, A.B
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.03.2005; Blackwell Science
• Subjects: Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; ethylene; ethylene receptor; Ethylenes - metabolism; ETR1; Fundamental and applied biological sciences. Psychology; Gene expression; gene expression regulation; Gene Expression Regulation, Plant; hormone receptors; Kinetics; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Lycopersicon esculentum - metabolism; membrane proteins; membrane‐associated receptor; messenger RNA; Metabolism; molecular sequence data; nucleotide sequences; plant hormone; Plant physiology and development; Plant populations; Plant Proteins - genetics; Plant Proteins - metabolism; protein binding; protein isoforms; Protein Isoforms - metabolism; quantitative analysis; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; RNA, Messenger - genetics; signal transduction; Solanum lycopersicum var. lycopersicum; Storage and secretion, pigments, phytochrome; Tomatoes; Yeast; ethylene receptor; plant hormone; Ethylene; Gene expression; ETR1; Arabidopsis thaliana; Signal transduction; Cruciferae; Dicotyledones; Angiospermae; Lycopersicon esculentum; Spermatophyta; Solanaceae; Kinetics; membrane-associated receptor
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313x.2004.02331.x

Ethylene signaling in plants is mediated by a family of ethylene receptors related to bacterial two-component regulators. Expression in yeast of ethylene-binding domains from the five receptor isoforms from Arabidopsis thaliana and five-receptor isoforms from tomato confirmed that all members of the family are capable of high-affinity ethylene-binding activity. All receptor isoforms displayed a similar level of ethylene binding on a per unit protein basis, while members of both subfamily I and subfamily II from Arabidopsis showed similar slow-release kinetics for ethylene. Quantification of receptor-isoform mRNA levels in receptor-deficient Arabidopsis lines indicated a direct correlation between total message level and total ethylene-binding activity in planta. Increased expression of remaining receptor isoforms in receptor-deficient lines tended to compensate for missing receptors at the level of mRNA expression and ethylene-binding activity, but not at the level of receptor signaling, consistent with specialized roles for family members in receptor signal output.