title: Citrate Accumulation-Related Gene Expression and/or Enzyme Activity Analysis Combined With Metabolomics Provide a Novel Insight for an Orange Mutant.
abstract: 'Hong Anliu' (HAL, Citrus sinensis cv. Hong Anliu) is a bud mutant of 'Anliu' (AL), characterized by a comprehensive metabolite alteration, such as lower accumulation of citrate, high accumulation of lycopene and soluble sugars in fruit juice sacs. Due to carboxylic acid metabolism connects other metabolite biosynthesis and/or catabolism networks, we therefore focused analyzing citrate accumulation-related gene expression profiles and/or enzyme activities, along with metabolic fingerprinting between 'HAL' and 'AL'. Compared with 'AL', the transcript levels of citrate biosynthesis- and utilization-related genes and/or the activities of their respective enzymes such as citrate synthase, cytosol aconitase and ATP-citrate lyase were significantly higher in 'HAL'. Nevertheless, the mitochondrial aconitase activity, the gene transcript levels of proton pumps, including vacuolar H(+)-ATPase, vacuolar H(+)-PPase, and the juice sac-predominant p-type proton pump gene (CsPH8) were significantly lower in 'HAL'. These results implied that 'HAL' has higher abilities for citrate biosynthesis and utilization, but lower ability for the citrate uptake into vacuole compared with 'AL'. Combined with the metabolites-analyzing results, a model was then established and suggested that the reduction in proton pump activity is the key factor for the low citrate accumulation and the comprehensive metabolite alterations as well in 'HAL'.
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Ling-Xia
authors.initials: LX
authors.lastname: Guo
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Cai-Yun
authors.initials: CY
authors.lastname: Shi
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Dong-Yuan
authors.initials: DY
authors.lastname: Ning
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Jing
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yang
authors.affiliation: Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, P.R. China.|College of Horticulture &Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Yong-Zhong
authors.initials: YZ
authors.lastname: Liu
mesh_terms: D000154:Aconitate Hydratase / Q000235:genetics; D002338:Carotenoids / Q000235:genetics; D002950:Citrate (si)-Synthase / Q000235:genetics; D019343:Citric Acid / Q000378:metabolism*; D002957:Citrus / Q000235:genetics*; D032084:Citrus sinensis / Q000235:genetics*; D005638:Fruit / Q000235:genetics; D000067030:Fruit and Vegetable Juices; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D000077276:Lycopene; D055432:Metabolomics / Q000379:methods; D017494:Proton Pumps / Q000235:genetics
chemical_list: D017494:Proton Pumps; D019343:Citric Acid; D002338:Carotenoids; D002950:Citrate (si)-Synthase; D000154:Aconitate Hydratase; D000077276:Lycopene