Integrative transcriptomic and metabolomic analyses reveal the flavonoid biosynthesis of Pyrus hopeiensis flowers under cold stress  

作　　者：Yongtan Li Jun Zhang Shijie Wang Haie Zhang Yichao Liu Minsheng Yang 

机构地区：[1]Forest Department,Forestry College,Hebei Agricultural University,Baoding,Hebei 071001,China [2]Hebei Key Laboratory for Tree Genetic Resources and Forest Protection,Baoding,Hebei 071001,China [3]Hebei Normal University of Science&Technology,Qinhuangdao,Hebei 066600,China [4]Institute of Landscaping,Hebei Academic of Forestry and Grassland,Shijiazhuang,Hebei 050061,China

出　　处：《Horticultural Plant Journal》2023年第3期395-413,共19页园艺学报（英文版）

基　　金：supported by the National Key Research and Development Plan“Research on protection and restoration of typical small populations of wild plants”(Grant No.2016YFC0503106)。

摘　　要：Low temperature is among the most restrictive factors to limit the yield and distribution of pear. Pyrus hopeiensis is a valuable wild resource.PCA showed that P. hopeiensis had strong cold resistance. In this study, the mRNA and metabolome sequencing of P. hopeiensis flower organs exposed to different low temperatures were performed to identify changes of genes and metabolites in response to low-temperature stress. A total of 4 851 differentially expressed genes(DEGs) were identified. Trend analysis showed that these DEGs were significantly enriched in profiles 19, 18, 7, 14, 1, 4 and 11. And the KEGG enrichment analysis showed that the DEGs in profile 18 were significantly enriched in flavone and flavonol biosynthesis. Besides, the expressed trends as well as GO and KEGG functional enrichment analyses of DEGs under cold and freezing stress showed significantly difference. Analyses of flavonoid-related pathways indicated that flavonoid structural genes had undergone significant changes. Correlation analysis showed that b HLH and MYB TFs may affect flavonoid biosynthesis by regulating structural gene expression. And PhMYB308 and PhMYB330 were likely candidate repressors of flavonoid biosynthesis by binding to a specific site in bHLH proteins. In total, 92 differentially accumulated metabolites(DAMs) were identified in P. hopeiensis flowers including 12 flavonoids. WGCNA results showed that coral 1, pink and brown 4 modules were closely associated with flavonoids and 11 MYBs and 15 bHLHs among the three modules may activate or inhibit the expression of 23 structural genes of flavonoid biosynthesis. Taken together, the results of this study provided a theoretical basis for further exploration of the molecular mechanisms of flavonoid biosynthesis and cold resistance of P. hopeiensis flower organs and our findings laid a foundation for further molecular breeding in cold-resistant pear varieties.

关 键 词：Pyrus hopeiensis Cold resistance of flower Transcriptome METABOLOME Flavonoid WGCNA 

分 类 号：S661.2[农业科学—果树学]