title: PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance.
abstract: Sweet cherry is a non-climacteric fruit and its ripening is regulated by abscisic acid (ABA) during fruit development. In this study, four cDNAs (PacCYP707A1-4) encoding 8'-hydroxylase, a key enzyme in the oxidative catabolism of ABA, were identified in sweet cherry fruits using tobacco rattle virus-induced gene silencing (VIGS) and particle bombardment approaches. Quantitative real-time PCR confirmed significant down-regulation of target gene transcripts in VIGS-treated cherry fruits. In PacCYP707A2-RNAi-treated fruits, ripening and fruit colouring were promoted relative to control fruits, and both ABA accumulation and PacNCED1 transcript levels were up-regulated by 140%. Silencing of PacCYP707A2 by VIGS significantly altered the transcripts of both ABA-responsive and ripening-related genes, including the ABA metabolism-associated genes NCED and CYP707A, the anthocyanin synthesis genes PacCHS, PacCHI, PacF3H, PacDFR, PacANS, and PacUFGT, the ethylene biosynthesis gene PacACO1, and the transcription factor PacMYBA. The promoter of PacMYBA responded more strongly to PacCYP707A2-RNAi-treated fruits than to PacCYP707A1-RNAi-treated fruits. By contrast, silencing of PacCYP707A1 stimulated a slight increase in fruit colouring and enhanced resistance to dehydration stress compared with control fruits. These results suggest that PacCYP707A2 is a key regulator of ABA catabolism that functions as a negative regulator of fruit ripening, while PacCYP707A1 regulates ABA content in response to dehydration during fruit development.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Pei
authors.initials: P
authors.lastname: Chen
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Dai
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, 1306 East University BouleVard, Tucson, AZ, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Yuan
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Kai
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Pei
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Suihuan
authors.initials: S
authors.lastname: He
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liang
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China Department of Chemistry and Biochemistry, University of Arizona, 1306 East University BouleVard, Tucson, AZ, USA.
authors.forename: Yushu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China pleng@cau.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Leng
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000222:Adaptation, Physiological / Q000235:genetics; D000872:Anthocyanins / Q000378:metabolism; D003890:Desiccation; D055864:Droughts; D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D027861:Prunus / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*
chemical_list: D000872:Anthocyanins; D005030:Ethylenes; D010940:Plant Proteins; D000040:Abscisic Acid; C036216:ethylene
keywords: ABA; CYP707A; VIGS.; cherry ripening; colouring; dehydration stress; particle bombardment