title: Microarray expression profiling of postharvest Ponkan mandarin (Citrus reticulata) fruit under cold storage reveals regulatory gene candidates and implications on soluble sugars metabolism.
abstract: Low temperature storage is widely applied to maintain citrus postharvest fruit quality. In this study, the transcriptional and metabolic changes in the pulp tissue of Citrus reticulata Blanco cv. "Ponkan" were studied for three successive months under cold storage by Affymetrix Citrus GeneChip and gas chromatography, respectively. As many as 2 161 differentially expressed transcripts were identified based on the bayesian hierarchical model. The statistical analysis of gene ontology revealed that defense/stress-related genes were induced quickly, while autophagy-related genes were overrepresented in the late sampling stages, suggesting that the functional shift may coincide with the subsequent steps of chilling development. We further classified the potential regulatory components and concluded that ethylene may play the crucial role in chilling development in this non-climacteric fruit. To cope with complex events, 53 upregulated transcription factors represented regulatory candidates. Within these, the AP2-EREBP, C2H2 and AS2 gene family were overrepresented. Cold storage also causes alterations in various metabolic pathways; a keen interest is paid in deciphering expression changes of soluble sugar genes as increased evidence that soluble sugars act as both osmolytes and metabolite signal molecules. Our results will likely facilitate further studies in this field with promising genetic candidates during chilling.
authors.affiliation: Key Laboratory of Horticulture Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, China.
authors.forename: Andan
authors.initials: A
authors.lastname: Zhu
authors.forename: Wenyun
authors.initials: W
authors.lastname: Li
authors.forename: Junli
authors.initials: J
authors.lastname: Ye
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Sun
authors.forename: Yuduan
authors.initials: Y
authors.lastname: Ding
authors.forename: Yunjiang
authors.initials: Y
authors.lastname: Cheng
authors.forename: Xiuxin
authors.initials: X
authors.lastname: Deng
mesh_terms: D050260:Carbohydrate Metabolism; D002957:Citrus / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D014157:Transcription Factors; C036216:ethylene