title: Analysis of the Xyloglucan Endotransglucosylase/Hydrolase Gene Family during Apple Fruit Ripening and Softening.
abstract: Ethylene and xyloglucan endotransglucosylase/hydrolase (XTH) genes were important for fruit ripening and softening in 'Taishanzaoxia' apple. In this study, we found it was ACS1-1/-1 homozygotes in 'Taishanzaoxia' apple, which determined the higher transcription activity of ACS1. XTH1, XTH3, XTH4, XTH5, and XTH9 were mainly involved in the early fruit softening independent of ethylene, while XTH2, XTH6, XTH7, XTH8, XTH10, and XTH11 were predominantly involved in the late fruit softening dependent on ethylene. Overexpression of XTH2 and XTH10 in tomato resulted in the elevated expression of genes involved in ethylene biosynthesis (ACS2, ACO1), signal transduction (ERF2), and fruit softening (XTHs, PG2A, Cel2, and TBG4). In summary, the burst of ethylene in 'Taishanzaoxia' apple was predominantly determined by ACS1-1/-1 genotype, and the differential expression of XTH genes dependent on and independent of ethylene played critical roles in the fruit ripening and softening. XTH2 and XTH10 may act as a signal switch in the feedback regulation of ethylene signaling and fruit softening.
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Zongying
authors.identifier: http://orcid.org/0000-0001-9440-3289
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Shandong Institute of Pomology , Tai'an, Shandong 271000, China.
authors.forename: Chuanzeng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Jingxuan
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Changzhi
authors.initials: C
authors.lastname: Qu
authors.affiliation: College of Life Science, Linyi University , Linyi, Shandong 276005, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Shujing
authors.initials: S
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Xiaoliu
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai'an, Shandong 271018, China.
authors.forename: Xuesen
authors.initials: X
authors.lastname: Chen
mesh_terms: D002681:China; D005030:Ethylenes / Q000096:biosynthesis; D005638:Fruit / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D016695:Glycosyltransferases / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics; D027845:Malus / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D005810:Multigene Family; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; C036216:ethylene; D016695:Glycosyltransferases; C473049:xyloglucan - xyloglucosyltransferase
keywords: XTH; apple; ethylene; fruit softening; gene expression