Rose (Rosa rugosa) petals are rich in diverse secondary metabolites, which have important physiological functions as well as great economic values. Currently, it remains unclear how saline and/or alkaline stress(es) influence the accumulation of secondary metabolites in rose. In this study, we analyzed the transcriptome and metabolite profiles of rose petals under aline–alkali stress and uncovered the induction mechanism underlying major metabolites. Dramatic changes were observed in the expression of 1363 genes and the abundances of 196 metabolites in petals in response to saline–alkali stress. These differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) are mainly associated with flavonoid and terpenoid metabolism and the reconstruction of cell walls. Of them, TERPENE SYNTHASE 31 (TPS31) overexpression in tobacco leaves driven by its own promoter resulted in significant alterations in the levels of diverse terpenoids, which were differentially influenced by saline–alkali stress. An integrated analysis of metabolomic and transcriptomic data revealed a high correlation between the abundances of flavonoids/terpenoids and the expression of the transcription factor MYB5. MYB5 may orchestrate the biosynthesis of sesquiterpenoids and proanthocyanidins through direct regulation of TPS31 and ANR expression under aline–alkali stress. Our finding facilitates improving the bioactive substance accumulation of rose petals by metabolic engineering.

中文翻译：

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盐碱胁迫通过玫瑰花瓣中的 MYB5-ANR/TPS31 级联反应影响原花青素和倍半萜类化合物的积累


玫瑰 （Rosa rugosa） 花瓣富含多种次生代谢物，具有重要的生理功能和巨大的经济价值。目前，尚不清楚盐水和/或碱性胁迫如何影响玫瑰中次生代谢物的积累。在这项研究中，我们分析了在碱胁迫下玫瑰花瓣的转录组和代谢物谱，并揭示了主要代谢物的诱导机制。在盐碱胁迫下，观察到花瓣中 1363 个基因的表达和 196 种代谢物的丰度发生巨大变化。这些差异表达基因 （DEGs） 和差异积累代谢物 （DAM） 主要与类黄酮和萜类化合物代谢以及细胞壁的重建有关。其中，由自身启动子驱动的 TERPENE SYNTHASE 31 （TPS31） 在烟叶中过表达导致不同萜类化合物水平的显着变化，这些萜类化合物受盐碱胁迫的不同影响。代谢组学和转录组学数据的综合分析显示，类黄酮/萜类化合物的丰度与转录因子 MYB5 的表达之间存在高度相关性。MYB5 可能在碱化应激下通过直接调节 TPS31 和 ANR 表达来协调倍半萜类化合物和原花青素的生物合成。我们的发现有助于通过代谢工程改善玫瑰花瓣的生物活性物质积累。