title: Identification of Differentially Expressed Genes Associated with Apple Fruit Ripening and Softening by Suppression Subtractive Hybridization.
abstract: Apple is one of the most economically important horticultural fruit crops worldwide. It is critical to gain insights into fruit ripening and softening to improve apple fruit quality and extend shelf life. In this study, forward and reverse suppression subtractive hybridization libraries were generated from 'Taishanzaoxia' apple fruits sampled around the ethylene climacteric to isolate ripening- and softening-related genes. A set of 648 unigenes were derived from sequence alignment and cluster assembly of 918 expressed sequence tags. According to gene ontology functional classification, 390 out of 443 unigenes (88%) were assigned to the biological process category, 356 unigenes (80%) were classified in the molecular function category, and 381 unigenes (86%) were allocated to the cellular component category. A total of 26 unigenes differentially expressed during fruit development period were analyzed by quantitative RT-PCR. These genes were involved in cell wall modification, anthocyanin biosynthesis, aroma production, stress response, metabolism, transcription, or were non-annotated. Some genes associated with cell wall modification, anthocyanin biosynthesis and aroma production were up-regulated and significantly correlated with ethylene production, suggesting that fruit texture, coloration and aroma may be regulated by ethylene in 'Taishanzaoxia'. Some of the identified unigenes associated with fruit ripening and softening have not been characterized in public databases. The results contribute to an improved characterization of changes in gene expression during apple fruit ripening and softening.
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Zongying
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Xiaohao
authors.initials: X
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Jingxuan
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Deyun
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Xu
authors.affiliation: College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Sumin
authors.initials: S
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Shujing
authors.initials: S
authors.lastname: Wu
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, New York, United States of America.
authors.forename: Zhangjun
authors.initials: Z
authors.lastname: Fei
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Shouqian
authors.initials: S
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, China.|College of Horticulture Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
authors.forename: Xuesen
authors.initials: X
authors.lastname: Chen
mesh_terms: D018744:DNA, Plant / Q000235:genetics; D020224:Expressed Sequence Tags / Q000378:metabolism; D005638:Fruit / Q000235:genetics*; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics*; D027845:Malus / Q000235:genetics*; D066251:Subtractive Hybridization Techniques / Q000379:methods
chemical_list: D018744:DNA, Plant