title: TIR1-like auxin-receptors are involved in the regulation of plum fruit development.
abstract: Ethylene has long been considered the key regulator of ripening in climacteric fruit. Recent evidence showed that auxin also plays an important role during fruit ripening, but the nature of the interaction between the two hormones has remained unclear. To understand the differences in ethylene- and auxin-related behaviours that might reveal how the two hormones interact, we compared two plum (Prunus salicina L.) cultivars with widely varying fruit development and ripening ontogeny. The early-ripening cultivar, Early Golden (EG), exhibited high endogenous auxin levels and auxin hypersensitivity during fruit development, while the late-ripening cultivar, V98041 (V9), displayed reduced auxin content and sensitivity. We show that exogenous auxin is capable of dramatically accelerating fruit development and ripening in plum, indicating that this hormone is actively involved in the ripening process. Further, we demonstrate that the variations in auxin sensitivity between plum cultivars could be partially due to PslAFB5, which encodes a TIR1-like auxin receptor. Two different PslAFB5 alleles were identified, one (Pslafb5) inactive due to substitution of the conserved F-box amino acid residue Pro61 to Ser. The early-ripening cultivar, EG, exhibited homozygosity for the inactive allele; however, the late cultivar, V9, displayed a PslAFB5/afb5 heterozygous genotype. Our results highlight the impact of auxin in stimulating fruit development, especially the ripening process and the potential for differential auxin sensitivity to alter important fruit developmental processes.
authors.affiliation: University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada Faculty of Agriculture, Damanhour University, Damanhour, Egypt.
authors.forename: Islam
authors.initials: I
authors.lastname: El-Sharkawy
authors.affiliation: University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada Faculty of Agriculture, Damanhour University, Damanhour, Egypt.
authors.forename: Sherif M
authors.initials: SM
authors.lastname: Sherif
authors.affiliation: The University of Sydney, Faculty of Agriculture, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Jones
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Castanet-Tolosan F-31326, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mila
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Prakash P
authors.initials: PP
authors.lastname: Kumar
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, Génomique et Biotechnologie des Fruits, Castanet-Tolosan F-31326, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.affiliation: University of Guelph, Department of Plant Agriculture. 4890 Victoria Av. N., P.O. Box 7000 Vineland Station, ON, L0R 2E0 Canada jsubrama@uoguelph.ca.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Jayasankar
mesh_terms: D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D027861:Prunus / Q000235:genetics / Q000378:metabolism*
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010940:Plant Proteins; C036216:ethylene
keywords: Auxin-receptors; Prunus salicina; auxin/ethylene crosstalk.; plum fruit development; protein–protein interaction; subcellular localization