Location: Vegetable Crops ResearchTitle: Transcriptomic and QTL analysis suggest candidate fruit shape factors in cucumber (Cucumis sativus) Author
Submitted to: Plant and Animal Genome
Publication Type: Abstract Only
Publication Acceptance Date: 11/3/2015
Publication Date: 1/8/2016
Citation: Colle, M., Weng, Y., Ophir, R., Sherman, A., Kang, Y., Grumet, R. 2016. Transcriptomic and QTL analysis suggest candidate fruit shape factors in cucumber (Cucumis sativus) [abstract]. Plant and Animal Genome. Paper No. P0073. Interpretive Summary:
Technical Abstract: Fruit size and shape are important determinants of market class and value in cucumber; however, underlying mechanisms regulating size and shape have not been identified. To gain insight into possible factors regulating cucumber fruit growth, we used a combined QTL and transcriptome approach to examine two sequenced cultivars representing extremes in fruit size and shape: ‘Gy14’ (pickling type; short, wide) and Chinese long ‘9930,’ (CL) (long, narrow). Based on our prior fruit growth transcriptome data, sets of genes that exhibited specific developmental pattern of expression were located with respect to fruit size QTL identified by SNP array analysis of F7:8RILs from ‘Gy14’x’CL’. Five putative transcription factor homologs with increased expression at late/post-exponential phase of fruit growth in the pickling cultivar ‘Vlaspik’ clustered to a region associated with fruit size QTL on chromosome 3. Examination of expression from 5 days pre-anthesis to 20 days post-pollination (dpp) showed that two of these genes, homologs of ATHB-2, [HOMOEBOX PROTEIN 2 (CsHB-2)] a gene that controls direction of cell expansion in Arabidopsis, and ETHYLENE RESPONSIVE ELEMENT BINDING FACTOR 3 (CsERF3), exhibited earlier and elevated expression in ‘CL’ relative to the pickling types ‘Gy14,‘Vlaspik’. Increased expression of CsHB-2 and CsERF3 in ‘CL’ correlated with onset of cell expansion and cell shape difference of ‘CL’ relative to the pickling types. Furthermore, the CsHB-2 allele in ‘CL’ had a deletion within the GAGA element in the 5’ NTR. Collectively, these results suggest potential role of these genes in the regulation of fruit size and shape in cucumber.