Ripening inhibition in the tomato Green-ripe mutant results from ectopic expression of a novel protein which disrupts ethylene signal transduction

US7947867B1 · kind B1 · utility

Assignee

• The United States of America, as represented by the Secretary of Agriculture · US

Inventors

• James Giovannoni · Ithaca, US
• Cornelius Barry · Haslett, US

Key dates

• Filing date: May 26, 2006
• Grant date: May 24, 2011
• Expiry date: Sep 18, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C12N15/8249
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

To achieve full development of the ripe phenotype, climacteric fruits, such as tomato, apple and banana, require synthesis, perception and signal transduction of the plant hormone ethylene. The non-ripening phenotype of the dominant Green-ripe (Gr) and Never-ripe 2 (Nr-2) mutants of tomato is the result of reduced ethylene responsiveness in fruit tissues. In addition a subset of ethylene responses associated with floral senescence, abscission and root elongation are also impacted in mutant plants but to a lesser extent. Using positional cloning we have identified an identical 334 by deletion in a gene of unknown biochemical function residing at the Gr/Nr-2 locus. Consistent with a dominant gain of function mutation, this deletion causes ectopic expression of GR/NR-2, which in turn leads to ripening inhibition. A CaMV35:GR transgene recreates the Gr/Nr-2 mutant phenotype but does not lead to a global reduction in ethylene responsiveness suggesting tissue-specific modulation of ethylene responses in tomato. GR/NR-2 encodes a novel evolutionary conserved membrane localized protein of unknown biochemical function that has not previously been associated with ethylene signaling. Because …