Evidence for regulation of columnar habit in apple by a putative 2OG-Fe(II) oxygenase

• Published in: The New phytologist Vol. 200; no. 4; pp. 993 - 999
• Main Authors: Wolters, Pieter J, Schouten, Henk J, Velasco, Riccardo, Si-Ammour, Azeddine, Baldi, Paolo
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.12.2013; Wiley Subscription Services, Inc
• Subjects: 2OG‐Fe(II) oxygenase; Apples; Arabidopsis - genetics; Chromosomes, Artificial, Bacterial - metabolism; columnar gene (Co); Deoxyribonucleic acid; DNA; Fruit trees; Fruits; Gene expression; Gene expression regulation; Gene Expression Regulation, Plant; Genes; Genetic Loci - genetics; Genomes; Genomics; Growth; Insertion; Iron; Leaf buds; Libraries; Malus - enzymology; Malus - genetics; Malus - growth & development; Malus × domestica (apple); Nucleotide sequence; Oxygenase; Oxygenases - genetics; Oxygenases - metabolism; Phenotype; Phenotypes; Plants; Plants, Genetically Modified; Polymerase chain reaction; Rapid reports; RNA; Sequence Analysis, DNA; tree architecture; Trees; Wijcik; tree architecture; Wijcik; Malus × domestica (apple); 2OG-Fe(II) oxygenase; columnar gene (Co)
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12580

Understanding the genetic mechanisms controlling columnar-type growth in the apple mutant ‘Wijcik’ will provide insights on how tree architecture and growth are regulated in fruit trees. In apple, columnar-type growth is controlled by a single major gene at the Columnar (Co) locus. By comparing the genomic sequence of the Co region of ‘Wijcik’ with its wild-type ‘McIntosh’, a novel non-coding DNA element of 1956 bp specific to Pyreae was found to be inserted in an intergenic region of ‘Wijcik’. Expression analysis of selected genes located in the vicinity of the insertion revealed the upregulation of the MdCo31 gene encoding a putative 2OG-Fe(II) oxygenase in axillary buds of ‘Wijcik’. Constitutive expression of MdCo31 in Arabidopsis thaliana resulted in compact plants with shortened floral internodes, a phenotype reminiscent of the one observed in columnar apple trees. We conclude that MdCo31 is a strong candidate gene for the control of columnar growth in ‘Wijcik’.