title: Characterization and Comparative Expression Profiling of Browning Response inMedinilla formosanaafter Cutting.
abstract: Plant browning is a recalcitrant problem forin vitroculture and often leads to poor growth of explants and even failure of tissue culture. However, the molecular mechanisms underlying browning-induced physiological processes remain unclear.Medinillais considered one of the most difficult genera for tissue culture owning to its severe browning. In the present study, intact aseptic plantlets ofMedinilla formosanaHayata previously obtained by ovary culture, were used to explore the characteristics and molecular mechanism of the browning response. Successive morphological and anatomical observations after cutting showed that the browning ofM. formosanawas not lethal but adaptive.De novotranscriptome and digital gene expression (DGE) profiling using Illumina high-throughput sequencing were then used to explore molecular regulation after cutting. About 7.5 million tags ofde novotranscriptome were obtained and 58,073 unigenes were assembled and annotated. A total of 6,431 differentially expressed genes (DEGs) at three stages after cutting were identified, and the expression patterns of these browning-related genes were clustered and analyzed. A number of putative DEGs involved in signal transduction and secondary metabolism were particularly studied and the potential roles of these cutting-responsive mRNAs in plant defense to diverse abiotic stresses are discussed. The DGE profiling data were also validated by quantitative RT-PCR analysis. The data obtained in this study provide an excellent resource for unraveling the molecular mechanisms of browning processes duringin vitrotissue culture, and lay a foundation for future studies to inhibit and eliminate browning damage.
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of Agriculture Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of Agriculture Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Yiting
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Agriculture Experiment Station, Zhejiang University Hangzhou, China.
authors.forename: Kunfeng
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of Agriculture Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Xijiao
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of Agriculture Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Chen
keywords: Medinilla; browning; cutting; gene expression profiling; high-throughput sequencing; tissue culture; transcriptome