High-Resolution Mapping of a Fruit Firmness-Related Quantitative Trait Locus in Tomato Reveals Epistatic Interactions Associated with a Complex Combinatorial Locus



Chapman, Natalie H, Bonnet, Julien, Grivet, Laurent, Lynn, James, Graham, Neil, Smith, Rebecca, Sun, Guiping, Walley, Peter G ORCID: 0000-0001-9166-6294, Poole, Mervin, Causse, Mathilde
et al (show 3 more authors) (2012) High-Resolution Mapping of a Fruit Firmness-Related Quantitative Trait Locus in Tomato Reveals Epistatic Interactions Associated with a Complex Combinatorial Locus. PLANT PHYSIOLOGY, 159 (4). pp. 1644-1657.

Access the full-text of this item by clicking on the Open Access link.

Abstract

Fruit firmness in tomato (Solanum lycopersicum) is determined by a number of factors including cell wall structure, turgor, and cuticle properties. Firmness is a complex polygenic trait involving the coregulation of many genes and has proved especially challenging to unravel. In this study, a quantitative trait locus (QTL) for fruit firmness was mapped to tomato chromosome 2 using the Zamir Solanum pennellii interspecific introgression lines (ILs) and fine-mapped in a population consisting of 7,500 F2 and F3 lines from IL 2-3 and IL 2-4. This firmness QTL contained five distinct subpeaks, Fir(s.p.)QTL2.1 to Fir(s.p.)QTL2.5, and an effect on a distal region of IL 2-4 that was nonoverlapping with IL 2-3. All these effects were located within an 8.6-Mb region. Using genetic markers, each subpeak within this combinatorial locus was mapped to a physical location within the genome, and an ethylene response factor (ERF) underlying Fir(s.p.)QTL2.2 and a region containing three pectin methylesterase (PME) genes underlying Fir(s.p.)QTL2.5 were nominated as QTL candidate genes. Statistical models used to explain the observed variability between lines indicated that these candidates and the nonoverlapping portion of IL 2-4 were sufficient to account for the majority of the fruit firmness effects. Quantitative reverse transcription-polymerase chain reaction was used to quantify the expression of each candidate gene. ERF showed increased expression associated with soft fruit texture in the mapping population. In contrast, PME expression was tightly linked with firm fruit texture. Analysis of a range of recombinant lines revealed evidence for an epistatic interaction that was associated with this combinatorial locus.

Item Type: Article
Uncontrolled Keywords: Chromosomes, Plant, Fruit, Chromosome Mapping, Epistasis, Genetic, Gene Expression Regulation, Plant, Recombination, Genetic, Base Pairing, Phenotype, Quantitative Trait Loci, Models, Genetic, Genetic Association Studies, Solanum lycopersicum
Depositing User: Symplectic Admin
Date Deposited: 02 Nov 2016 09:27
Last Modified: 17 Feb 2023 17:56
DOI: 10.1104/pp.112.200634
Open Access URL: http://www.plantphysiol.org/content/159/4/1644.lon...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3004249