title: Morphological observation, RNA-Seq quantification, and expression profiling: novel insight into grafting-responsive carotenoid biosynthesis in watermelon grafted onto pumpkin rootstock.
abstract: Watermelon is an important and economical horticultural crop in China, where ~20% of the plants are grafted. The development of grafted watermelon fruit involves a diverse range of gene interactions that results in dynamic changes in fruit. However, the molecular mechanisms underlying grafting-induced fruit quality change are unclear. In the present study, we measured the lycopene content by high-performance liquid chromatography and used RNA-Seq (quantification) to perform a genome-wide transcript analysis of fruits from watermelon grafted onto pumpkin rootstock (pumpkin-grafted watermelon, PGW), self-grafted watermelon (SGW), and non-grafted watermelon (NGW). The results showed variation in the lycopene content in the flesh of PGW fruits, first increasing and then decreasing in the four stages, which was different from the trend in the flesh of NGW and SGW fruits. The transcriptome profiling data provided new information on the grafting-induced gene regulation of lycopene biosynthesis during fruit growth and development. The expression levels of 33 genes from 8 gene families (GGPS, PSY, PDS, ZDS, CRTISO, LCYb, LCYe, and CHY) related to lycopene biosynthesis, which play critical roles in fruit coloration and contribute significantly to fruit phytonutrient values, were monitored during the four periods of fruit development in watermelon. Compared with those of NGW and SGW, 14 genes were differentially expressed in PGW during fruit development, suggesting that these genes possibly help to mediate lycopene biosynthesis in grafted watermelon fruit. Our work provides some novel insights into grafting-responsive carotenoid metabolism and its potential roles during PGW fruit development and ripening.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.|Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Liu
authors.affiliation: Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Xingping
authors.initials: X
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Man
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Hou
authors.affiliation: Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Aisheng
authors.initials: A
authors.lastname: Xiong
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics; D002338:Carotenoids / Q000096:biosynthesis*; D029773:Citrullus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D028464:Cucurbita / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D000077276:Lycopene; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027343:Rhizome / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017423:Sequence Analysis, RNA
chemical_list: D010940:Plant Proteins; D018749:RNA, Plant; D002338:Carotenoids; D000077276:Lycopene
keywords: RNA-Seq quantification; grafting; lycopene biosynthesis; pumpkin; watermelon