title: Transcriptome comparison of global distinctive features between pollination and parthenocarpic fruit set reveals transcriptional phytohormone cross-talk in cucumber (Cucumis sativus L.).
abstract: Parthenocarpy is an important trait determining yield and quality of fruit crops. However, the understanding of the mechanisms underlying parthenocarpy induction is limited. Cucumber (Cucumis sativus L.) is abundant in parthenocarpic germplasm resources and is an excellent model organism for parthenocarpy studies. In this study, the transcriptome of cucumber fruits was studied using RNA sequencing (RNA-Seq). Differentially expressed genes (DEGs) of set fruits were compared against aborted fruits. Distinctive features of parthenocarpic and pollinated fruits were revealed by combining the analysis of the transcriptome together with cytomorphological and physiological analysis. Cell division and the transcription of cell division genes were found to be more active in parthenocarpic fruit. The study also indicated that parthenocarpic fruit set is a high sugar-consuming process which is achieved via enhanced carbohydrate degradation through transcription of genes that lead to the breakdown of carbohydrates. Furthermore, the evidence provided by this work supports a hypothesis that parthenocarpic fruit set is induced by mimicking the processes of pollination/fertilization at the transcriptional level, i.e. by performing the same transcriptional patterns of genes inducing pollination and gametophyte development as in pollinated fruit. Based on the RNA-Seq and ovary transient expression results, 14 genes were predicted as putative parthenocarpic genes. The transcription analysis of these candidate genes revealed auxin, cytokinin and gibberellin cross-talk at the transcriptional level during parthenocarpic fruit set.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaThese authors contributed equally to this work.
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Shanxi Agricultural University, Shanxi 030801, ChinaThese authors contributed equally to this work.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaThese authors contributed equally to this work.
authors.forename: Li
authors.initials: L
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tinglin
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Qinwei
authors.initials: Q
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Qunfeng
authors.initials: Q
authors.lastname: Lou
authors.affiliation: Key Laboratory of Horticultural Crops Genetic Improvement of Ministry of Agriculture, Sino-Dutch Joint Lab of Horticultural Genomics Technology, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Sanwen
authors.initials: S
authors.lastname: Huang
authors.affiliation: Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 400044, China.
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China jfchen@njau.edu.cn.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Chen
mesh_terms: D002455:Cell Division; D032461:Chromosomes, Plant / Q000235:genetics*; D018553:Cucumis sativus / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D003583:Cytokinins / Q000378:metabolism; D015536:Down-Regulation; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D010312:Parthenogenesis; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics; D054817:Pollination; D017423:Sequence Analysis, RNA; D059467:Transcriptome; D015854:Up-Regulation
chemical_list: D003583:Cytokinins; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins
keywords: Cucumber (Cucumis sativus L.); Fruit set; Parthenocarpy; Transcriptome