Comparative Metabolomic and Transcriptome Analysis Reveal Distinct Flavonoid Biosynthesis Regulation Between Petals of White and Purple Phalaenopsis amabilis
- 21 Downloads
Orchids (Phalaenopsis amabilis), renowned for their extraordinary floral diversity which implies the complex flower color development, are one of the most valuable research materials for molecular biology studies. However, the genetic mechanisms underlying flower color formation in this non-model plant remain unclear. Here, the biochemical and molecular basis of the flavonoid/anthocyanin biosynthesis between purple petal cultivar (PP) and white petal cultivar (WP) was investigated. The results revealed that 142 differential flavonoid-related metabolites were identified using LC–MS/MS method, and the primary anthocyanins were identified as cyanidin derivatives. Moreover, RNA-seq revealed a total of 9523 upregulated and 6941 downregulated genes were detected. GO and KEGG analysis of DEGs indicated metabolic pathways were preferentially upregulated in PP. The expression of most known genes encoding the enzymes in anthocyanin and related derivative biosynthesis was significantly higher in PP than in WP, especially the downstream ones. We hypothesized that altered flavanone and flavone accumulation may lead to pigment elimination in WP, and the limited flux in cyanidin biosynthesis pathway seems to be the most likely reason for the colorless petal. Besides, 115 differentially expressed regulatory genes relating to anthocyanin biosynthesis were also detected, including MYB, bHLH, WD40, WRKY, MADS and bZIP. Subsequently, high consistency was observed between the results of qRT-PCR and those of RNA-seq. collectively, this study provides a comprehensive metabolic and transcriptional dataset for Phalaenopsis, the informative list of candidate structural and regulatory genes associated with purple trait offer a valuable opportunity to unravel the genetic mechanism underlying flower color formation in Phalaenopsis.
KeywordsAnthocyanin biosynthesis Differentially expressed genes Metabolomic analysis Phalaenopsis amabilis Transcriptome sequencing
Phenylalanine ammonia lyase
UPD glucose: flavonoid-3-O-glucosyltransferase
High-performance liquid chromatography
Quantitative real-time PCR
The authors thank Mingzhi Li (Genepioneer Biotechnologies, Nanjing, China) for the assistance in transcriptome data analysis. This work was supported by National Natural Science Foundation of China (31700226), Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), Natural Science Foundation of Jiangsu Province (BK20160215), Graduate Innovation Project of Jiangsu Normal University (KYCX17-1619), and Science and Technology Program of Ministry of Housing and Urban–Rural Development of China (2016-K1-028).
MZ and XM designed the experiments, analyzed the data and wrote the manuscript. TD and ZL analyzed the data and improved manuscript quality. XM, GL, LG, YS, JL and XW analyzed the data and performed the experiments. All authors have read and approved the final manuscript.
Compliance with Ethical Standards
Conflict of interest
The authors declare no conflict of interest.
- Chen W, Gong L, Guo Z, Wang W, Zhang H, Liu X, Yu S, Xiong L, Luo J (2013) A novel integrated method for large-scale detection, identification, and quantification of widely targeted metabolites: application in the study of rice metabolomics. Molecular Plant 6(6):1769–1780PubMedCrossRefGoogle Scholar
- Lloyd A, Brockman A, Aguirre L, Campbell A, Bean A, Cantero A, Gonzalez A (2017) Advances in the MYB-bHLH-WD repeat (MBW) pigment regulatory model: addition of a WRKY factor and co-option of an anthocyanin MYB for betalain regulation. Plant Cell Physiol 58(9):1431–1441PubMedPubMedCentralCrossRefGoogle Scholar
- Oh JH, Lee YJ, Byeon EJ, Kang BC, Kyeoung DS, Kim CK (2018) Whole-genome resequencing and transcriptomic analysis of genes regulating anthocyanin biosynthesis in black rice plants. Biotechnology 8(2):115Google Scholar
- Zhao ZC, Hu GB, Hu FC, Wang HC, Yang ZY, Lai B (2012) The UDP glucose: flavonoid-3-O-glucosyltransferase (UFGT) gene regulates anthocyanin biosynthesis in litchi (Litchi chinesis Sonn.) during fruit coloration. Mol Biol Rep 39(6):6409–6415. https://doi.org/10.1007/s11033-011-1303-3 CrossRefPubMedGoogle Scholar