title: Identification and mapping of Tril, a homeodomain-leucine zipper gene involved in multicellular trichome initiation in Cucumis sativus.
abstract: CONCLUSIONS
  Using map-based cloning of Tril gene, we identified a homeodomain-leucine zipper gene involved in the initiation of multicellular trichomes (including the spines of fruit) in cucumber.
  Fruit spines are a special type of trichome that impacts the quality and appearance of cucumber (Cucumis sativus L.) fruit. Scanning electron microscopy revealed that the trichome-less (tril) mutant originating from European greenhouse cucumber has a completely glabrous phenotype on cotyledons, hypocotyls, young leaves, fruits, and fruit stalks. Genetic analysis revealed that tril was inherited as a recessive allele at a single locus. Using 1058 F2 individuals derived from a cross between cucumber tril mutant CGN19839 and the micro-trichome (mict) mutant 06-2, tril was mapped to chromosome 6, and narrowed down to a 37.4 kb genomic region which carries seven predicted genes. Genetic and molecular analyses revealed that gene Cucsa.045360 is a possible candidate gene for the differentiation of epidermal cells to trichomes. It is a member of the class IV homeodomain-leucine zipper (HD-Zip IV) family and encodes homeodomain and START domain, sharing 66.7% predicted amino acid sequence identity to PROTODERMAL FACTOR2 (PDF2) and 35.0% to GLABRA2 (GL2) of Arabidopsis. The homeobox domain had changed amino acid sequence because of an insertion in tril mutant. The results of genetic analysis and transcriptome profiling indicated that the Tril gene had an epistatic effect on the Mict gene in trichome development. Phenotypes of the tril mutant such as glabrous fruits and female flowers at every node could be used in developing new cultivars.
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.
authors.forename: Yun-Li
authors.initials: YL
authors.lastname: Wang
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.
authors.forename: Jing-tao
authors.initials: JT
authors.lastname: Nie
authors.affiliation: Hunan Vegetable Research Institute, Hunan Academy of Agriculture Sciences, Changsha, 410125, China.
authors.forename: Hui-Ming
authors.initials: HM
authors.lastname: Chen
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.
authors.forename: Chun-li
authors.initials: CL
authors.lastname: Guo
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Pan
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.
authors.forename: Huan-Le
authors.initials: HL
authors.lastname: He
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China. jspan71@sjtu.edu.cn.
authors.forename: Jun-Song
authors.initials: JS
authors.lastname: Pan
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China. cairun@sjtu.edu.cn.
authors.forename: Run
authors.initials: R
authors.lastname: Cai
mesh_terms: D002874:Chromosome Mapping; D018553:Cucumis sativus / Q000235:genetics* / Q000254:growth & development; D018744:DNA, Plant / Q000235:genetics; D004843:Epistasis, Genetic; D005638:Fruit / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D005819:Genetic Markers; D018398:Homeodomain Proteins / Q000235:genetics*; D016350:Leucine Zippers; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D059467:Transcriptome; D064201:Trichomes / Q000254:growth & development*
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers; D018398:Homeodomain Proteins; D010940:Plant Proteins