title: Fine mapping and identification of candidate genes for the sy-2 locus in a temperature-sensitive chili pepper (Capsicum chinense).
abstract: The sy - 2 temperature-sensitive gene from Capsicum chinense was fine mapped to a 138.8-kb region at the distal portion of pepper chromosome 1. Based on expression analyses, two putative F-box genes were identified as sy - 2 candidate genes. Seychelles-2 ('sy-2') is a temperature-sensitive natural mutant of Capsicum chinense, which exhibits an abnormal leaf phenotype when grown at temperatures below 24 °C. We previously showed that the sy-2 phenotype is controlled by a single recessive gene, sy-2, located on pepper chromosome 1. In this study, a high-resolution genetic and physical map for the sy-2 locus was constructed using two individual F2 mapping populations derived from a cross between C. chinense mutant 'sy-2' and wild-type 'No. 3341'. The sy-2 gene was fine mapped to a 138.8-kb region between markers SNP 5-5 and SNP 3-8 at the distal portion of chromosome 1, based on comparative genomic analysis and genomic information from pepper. The sy-2 target region was predicted to contain 27 genes. Expression analysis of these predicted genes showed a differential expression pattern for ORF10 and ORF20 between mutant and wild-type plants; with both having significantly lower expression in 'sy-2' than in wild-type plants. In addition, the coding sequences of both ORF10 and ORF20 contained single nucleotide polymorphisms (SNPs) causing amino acid changes, which may have important functional consequences. ORF10 and ORF20 are predicted to encode F-box proteins, which are components of the SCF complex. Based on the differential expression pattern and the presence of nonsynonymous SNPs, we suggest that these two putative F-box genes are most likely responsible for the temperature-sensitive phenotypes in pepper. Further investigation of these genes may enable a better understanding of the molecular mechanisms of low temperature sensitivity in plants.
authors.affiliation: Department of Plant Science and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Plant Science and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Jelli
authors.initials: J
authors.lastname: Venkatesh
authors.affiliation: Department of Plant Science and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Yeong Deuk
authors.initials: YD
authors.lastname: Jo
authors.affiliation: Department of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors.forename: Sota
authors.initials: S
authors.lastname: Koeda
authors.affiliation: Department of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hosokawa
authors.affiliation: Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, 232-916, Korea.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Keygene N.V., P.O. Box 216, 6700 AE, Wageningen, The Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Goritschnig
authors.affiliation: Department of Plant Science and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea. bk54@snu.ac.kr.
authors.forename: Byoung-Cheorl
authors.initials: BC
authors.lastname: Kang
mesh_terms: D002212:Capsicum / Q000235:genetics*; D003080:Cold Temperature; D018744:DNA, Plant / Q000235:genetics; D044783:F-Box Proteins / Q000235:genetics*; D017343:Genes, Plant; D005808:Genes, Recessive; D016366:Open Reading Frames; D010641:Phenotype; D020161:Physical Chromosome Mapping; D020641:Polymorphism, Single Nucleotide
chemical_list: D018744:DNA, Plant; D044783:F-Box Proteins