1. The major-effect quantitative trait locus Fnl7.1 encodes a late embryogenesis abundant protein associated with fruit neck length in cucumber
- Author
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Qiang Xu, Xiaohua Qi, Liu Qianya, Xuewen Xu, Xuehao Chen, Chenxi Wei, and Wenqing Qu
- Subjects
0106 biological sciences ,0301 basic medicine ,Candidate gene ,QTL ,Quantitative Trait Loci ,India ,Locus (genetics) ,Single-nucleotide polymorphism ,Plant Science ,Biology ,Quantitative trait locus ,01 natural sciences ,03 medical and health sciences ,Gene mapping ,Gene expression ,late embryogenesis abundant protein ,fruit neck length ,Gene ,Phylogeny ,Research Articles ,Genetics ,Cucumber ,Bulked segregant analysis ,030104 developmental biology ,Phenotype ,Fruit ,fine genetic mapping ,Cucumis sativus ,Agronomy and Crop Science ,010606 plant biology & botany ,Biotechnology ,Research Article - Abstract
Summary Fruit neck length (FNL) is an important quality trait in cucumber because it directly affects its market value. However, its genetic basis remains largely unknown. We identified a candidate gene for FNL in cucumber using a next‐generation sequencing‐based bulked segregant analysis in F2 populations, derived from a cross between Jin5‐508 (long necked) and YN (short necked). A quantitative trait locus (QTL) on chromosome 7, Fnl7.1, was identified through a genome‐wide comparison of single nucleotide polymorphisms between long and short FNL F2 pools, and it was confirmed by traditional QTL mapping in multiple environments. Fine genetic mapping, sequences alignment and gene expression analysis revealed that CsFnl7.1 was the most likely candidate Fnl7.1 locus, which encodes a late embryogenesis abundant protein. The increased expression of CsFnl7.1 in long‐necked Jin5‐508 may be attributed to mutations in the promoter region upstream of the gene body. The function of CsFnl7.1 in FNL control was confirmed by its overexpression in transgenic cucumbers. CsFnl7.1 regulates fruit neck development by modulating cell expansion. Probably, this is achieved through the direct protein–protein interactions between CsFnl7.1 and a dynamin‐related protein CsDRP6 and a germin‐like protein CsGLP1. Geographical distribution differences of the FNL phenotype were found among the different cucumber types. The East Asian and Eurasian cucumber accessions were highly enriched with the long‐necked and short‐necked phenotypes, respectively. A further phylogenetic analysis revealed that the Fnl7.1 locus might have originated from India. Thus, these data support that the CsFnl7.1 has an important role in increasing cucumber FNL.
- Published
- 2019