title: Assessing the genetic variation ofTy-1andTy-3alleles conferring resistance to tomato yellow leaf curl virus in a broad tomato germplasm.
abstract: Tomato yellow leaf curl virus (TYLCV) hampers tomato production worldwide. Our previous studies have focussed on mapping and ultimately cloning of the TYLCV resistance genesTy-1andTy-3. Both genes are derived fromSolanum chilenseand were shown to be allelic. They code for an RNA-dependent RNA polymerase (RDR) belonging to the RDRγ type defined by a DFDGD catalytic domain. In this study, we first fine-mapped the TYLCV resistance inS. chilenseLA1932, LA1960 and LA1971. Results showed that chromosomal intervals of the causal genes in these TYLCV-resistant accessions overlap and cover the region whereTy-1/Ty-3is located. Further, virus-induced gene silencing was used to silenceTy-1/Ty-3in tomato lines carrying TYLCV resistance introgressed fromS. chilenseLA1932, LA1938 and LA1971. Results showed that silencingTy-1/Ty-3compromised the resistance in lines derived fromS. chilenseLA1932 and LA1938. The LA1971-derived material remained resistant upon silencingTy-1/Ty-3. Further, we studied the allelic variation of theTy-1/Ty-3gene by examining cDNA sequences from nineS. chilense-derived lines/accessions and more than 80 tomato cultivars, landraces and accessions of related wild species. The DFDGD catalytic domain of theTy-1/Ty-3gene is conserved among all tomato lines and species analysed. In addition, the 12 base pair insertion at the 5-prime part of theTy-1/Ty-3gene was found not to be specific for the TYLCV resistance allele. However, compared with the susceptiblety-1allele, theTy-1/Ty-3allele is characterized by three specific amino acids shared by seven TYLCV-resistantS. chilenseaccessions or derived lines. Thus,Ty-1/Ty-3-specific markers can be developed based on these polymorphisms. Elevated transcript levels were observed for all testedS. chilenseRDRalleles (bothTy-1andty-1alleles), demonstrating that elevated expression level is not a good selection criterion for a functionalTy-1/Ty-3allele.
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.|Graduate School Experimental Plant Sciences, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Myluska
authors.initials: M
authors.lastname: Caro
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.|Rijk Zwaan Breeding B.V., Burgemeester Crezéélaan 40, 2678 KX De Lier, The Netherlands.
authors.forename: Maarten G
authors.initials: MG
authors.lastname: Verlaan
authors.affiliation: Instituto Universitario de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV) (University Institute for Conservation and Improvement of Agrobiodiversity), Ciudad Politécnica de la Innovación (CPI), Universitat Politècnica de València, Camino de Vera, s/n Edificio 8E escalera J, 46022 Valencia, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Julián
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Finkers
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Anne-Marie A
authors.initials: AA
authors.lastname: Wolters
authors.affiliation: Gulf Coast Research and Education Center, University of Florida, 14625 CR 672, Wimauma, FL 33598 USA.
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Hutton
authors.affiliation: Gulf Coast Research and Education Center, University of Florida, 14625 CR 672, Wimauma, FL 33598 USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Scott
authors.affiliation: Laboratory of Virology, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Kormelink
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Richard G F
authors.initials: RGF
authors.lastname: Visser
authors.affiliation: Instituto Universitario de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV) (University Institute for Conservation and Improvement of Agrobiodiversity), Ciudad Politécnica de la Innovación (CPI), Universitat Politècnica de València, Camino de Vera, s/n Edificio 8E escalera J, 46022 Valencia, Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Díez
authors.affiliation: Instituto Universitario de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV) (University Institute for Conservation and Improvement of Agrobiodiversity), Ciudad Politécnica de la Innovación (CPI), Universitat Politècnica de València, Camino de Vera, s/n Edificio 8E escalera J, 46022 Valencia, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Pérez-de-Castro
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Bai
keywords: Breeding; RNA-dependent RNA polymerase (RDR); Resistance; Tomato; Tomato yellow leaf curl virus (TYLCV); Virus-induced gene silencing (VIGS)