title: Low Temperature Induced Changes in Citrate Metabolism in Ponkan (Citrus reticulata Blanco cv. Ponkan) Fruit during Maturation.
abstract: Citrate is the most important organic acid in citrus fruit, and its concentration in fruit cells is regulated mainly by the balance between synthesis and degradation. Ponkan (Citrus reticulate Blanco cv. Ponkan) is one of the major citrus cultivars grew in China, and the fruit are picked before fully mature to avoid bad weather. Greenhouse production is widely used to prolong the maturation period and improve the quality of Ponkan fruit by maintaining adequate temperature and providing protection from adverse weather. In this research, Ponkan fruit cultivated in either a greenhouse or open field were used to investigate differences in the expression of genes related to citrate metabolism during maturation in the two environments. The citrate contents were higher in open field fruit, and were mainly correlated with expressions of CitPEPCs, CitCSs, CitAco3 and CitGAD4, which were significantly increased. In addition, the impacts of low temperature (LT) and water stress (WS) on citrate metabolism in Ponkan were investigated during fruit maturation. The citrate contents in LT fruit were significantly increased, by between 1.4-1.9 fold, compared to the control; it showed no significant difference in fruit with water stress treatment compared to the control fruit. Furthermore, the expressions of CitPEPCs, CitCSs, CitAco3 and CitGAD4 were significantly increased in response to LT treatment, but showed no significant difference in WS compared to the control fruit. Thus, it can be concluded that low temperature may be the main factor influencing citrate metabolism during maturation in Ponkan fruit.
authors.affiliation: Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, P. R. China.|Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, Beijing, P. R. China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qian
authors.affiliation: Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, P. R. China.
authors.forename: Chenning
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Quzhou Academy of Agricultural Science, Quzhou, P. R. China.
authors.forename: Dengliang
authors.initials: D
authors.lastname: Wang
authors.affiliation: Quzhou Academy of Agricultural Science, Quzhou, P. R. China.
authors.forename: Chunrong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, Beijing, P. R. China.
authors.forename: Zhidong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, P. R. China.
authors.forename: Chongde
authors.initials: C
authors.lastname: Sun
authors.affiliation: Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, P. R. China.
authors.forename: Kunsong
authors.initials: K
authors.lastname: Chen
mesh_terms: D019343:Citric Acid / Q000378:metabolism*; D002957:Citrus / Q000254:growth & development / Q000378:metabolism*; D003080:Cold Temperature
chemical_list: D019343:Citric Acid