Towards a TILLING platform for functional genomics in Piel de Sapo melons

• Main Authors: Pujol Marta, Troadec Christelle, Monforte Antonio J, Roig Cristina, Esteras Cristina, Xu Meihong, González Mireia, Nuez Fernando, Bendahmane Abdelhafid, Garcia-Mas Jordi, Picó Belén
• Format: Article
• Language: English
• Published: BMC 2011-08-01
• Series: BMC Research Notes
• Subjects: <it>Cucumis melo</it>; <it>inodorus</it>; TILLING; mutant; disease resistance; fruit quality
• Online Access: http://www.biomedcentral.com/1756-0500/4/289

<p>Abstract</p> <p>Background</p> <p>The availability of genetic and genomic resources for melon has increased significantly, but functional genomics resources are still limited for this crop. TILLING is a powerful reverse genetics approach that can be utilized to generate novel mutations in candidate genes. A TILLING resource is available for <it>cantalupensis </it>melons, but not for <it>inodorus </it>melons, the other main commercial group.</p> <p>Results</p> <p>A new ethyl methanesulfonate-mutagenized (EMS) melon population was generated for the first time in an andromonoecious non-climacteric <it>inodorus </it>Piel de Sapo genetic background. Diverse mutant phenotypes in seedlings, vines and fruits were observed, some of which were of possible commercial interest. The population was first screened for mutations in three target genes involved in disease resistance and fruit quality (<it>Cm-PDS</it>, <it>Cm-eIF4E </it>and <it>Cm-eIFI(iso)4E</it>). The same genes were also tilled in the available monoecious and climacteric <it>cantalupensis </it>EMS melon population. The overall mutation density in this first Piel de Sapo TILLING platform was estimated to be 1 mutation/1.5 Mb by screening four additional genes (<it>Cm-ACO1</it>, <it>Cm-NOR</it>, <it>Cm-DET1 </it>and <it>Cm-DHS</it>). Thirty-three point mutations were found for the seven gene targets, six of which were predicted to have an impact on the function of the protein. The genotype/phenotype correlation was demonstrated for a loss-of-function mutation in the <it>Phytoene desaturase </it>gene, which is involved in carotenoid biosynthesis.</p> <p>Conclusions</p> <p>The TILLING approach was successful at providing new mutations in the genetic background of Piel de Sapo in most of the analyzed genes, even in genes for which natural variation is extremely low. This new resource will facilitate reverse genetics studies in non-climacteric melons, contributing materially to future genomic and breeding studies.</p>