The roots of Taraxacum kok-saghyz Rodin (TKS) are well-known and valued for their rubber-producing ability. Therefore, research on the analysis and detection of metabolites from the roots of TKS have been reported in previous studies. However, all of these studies have the shortcoming of focusing on only the rubber of TKS, without profiling the other metabolites in a systematic and comprehensive way. Here, the primary and secondary metabolites from the leaves of TKS were investigated using UPLC–ESI–MS/MS, and a total of 229 metabolites were characterized. Carboxylic acid derivatives, fatty acyls, phenols, and organooxygen compounds were found to be the major metabolites of TKS. The transcriptome data indicated that ribosomal, glycolysis/gluconeogenesis, phenylpropanoid biosynthesis, and linoleic acid metabolism genes were significantly differentially expressed. This study is the first to report the differences in the metabolic and transcriptome profiles of TKS leaves under exogenous ethephon spray, which improves our understanding of the main metabolites and their molecular mechanisms in TKS leaves.
The medicinal plant Spatholobus suberectus Dunn is easily exposed to shade stress during growth, but its shade responses and shade stress resistant mechanisms have not been clarified. In this study, shade treatments including four attenuated sunlight intensities (100%, 60%, 40%, and 10%) and three shade durations (30 d, 45 d, and 60 d) were applied to S. suberectus. The shade-induced morphological indicators, phytohormonal regulations, metabolic flavonoids contents, transcriptomic flavonoid pathway gene expressions, and stress physiological changes of S. suberectus were analyzed. The putative promoter cis-regulatory elements (CREs) of 18 flavonoid biosynthetic pathway genes were identified. Results showed the stem growth indicators of S. suberectus were better at 40% light intensity. Phytohormones were involved in the shade-induced responses. Short-term shade (30 d) increased total flavonoids, gallated catechins and especially epigallocatechin gallate contents and favored for boosting medicinal value. Long-term shade (45 d, 60 d) tended to decrease flavonoids. The shade-induced flavonoids changes were attributed to their corresponding biosynthesizing genes expression variations. The high antioxidant capacity and the presence of phytohormone-, stress-, and development-related CREs provided the basis for stress resistance. In conclusion, the multiple responses under shade and the CREs analysis elucidated S. suberectus’ shade tolerance.