Metabolic Profiling and Transcriptome Analysis Reveal the Key Role of Flavonoids in Internode Coloration of Phyllostachys violascens cv. Viridisulcata

Abstract

Bamboo, being an ornamental plant, has myriad aesthetic and economic significance. Particularly, Phyllostachys violascens cv. Viridisulcata contains an internode color phenotype in variation in green and yellow color between the sulcus and culm, respectively. This color variation is unique, but the underlying regulatory mechanism is still unknown. In this study, we used metabolomic and transcriptomic strategies to reveal the underlying mechanism of variation in internode color. A total of 81 metabolites were identified, and among those, prunin as a flavanone and rhoifolin as a flavone were discovered at a high level in the culm. We also found 424 differentially expressed genes and investigated three genes (PvGL, PvUF7GT, and PvC12RT1) that might be involved in prunin or rhoifolin biosynthesis. Their validation by qRT-PCR confirmed high transcript levels in the culm. The results revealed that PvGL, PvUF7GT, and PvC12RT1 might promote the accumulation of prunin and rhoifolin which were responsible for the variation in internode color of P. violascens. Our study also provides a glimpse into phenotypic coloration and is also a valuable resource for future studies.

Integrative analyses of morphology, physiology, and transcriptional expression profiling reveal miRNAs involved in culm color in bamboo

“…Available evidence indicates that CHS, CHI, F3H, and ANS are essential for flavonoid biosynthesis (Vogt, 2010 ). A previous study showed that the high transcript abundances of PvCHS and PvCHI were detected in green sulcus and yellow culm of P. violascens , despite the significant difference in flavonoid content (Wei et al, 2021 ). Compared with the Lv sample, CHS was significantly repressed and two metabolites (naringenin chalcone and naringenin) of the Bai sample were also decreased (Wang et al, 2020a ).…”

“…In P. violascens cv. Viridisulcata, the flavonoid content of yellow stems was significantly higher than that of the green sulcus in the same bamboo culm (Wei et al, 2021 ). Different results were obtained in this study; the flavonoid and carotenoid contents of DGM were higher than those of CYP ( Figures 2D , E ), despite the fact that DGM and CYP bamboo were born on the same rhizome.…”

“…Similar results were observed in the present study ( Figures 2B , C ). Many studies have shown that flavonoids, carotenoids, and anthocyanins may be involved in plant coloration (Hu et al, 2020 ; Jiang et al, 2020 ; Wei et al, 2021 ). In P. violascens cv.…”

“…Viridisulcata, from which 81 metabolites and 424 differentially expressed genes (DEGs) were identified. Prunin is a flavanone and rhoifolin, which was discovered to be present at a high level in the culm; PvGL, PvUF7GT , and PvC12RT1 , were involved in prunin or rhoifolin biosynthesis and showed high transcript levels (Wei et al, 2021 ). RNA-seq technology was applied to investigate the culm color variation of Bambusa oldhamii , and 449 key DEGs and 21 differentially expressed transcription factors (TF) were discovered by comparing culm skin samples of B. oldhamii and B. oldhamii f. revolute .…”

Characterization of color variation in bamboo sheath of Chimonobambusa hejiangensis by UPLC-ESI-MS/MS and RNA sequencing

“…With the rapid development and wide application of high-throughput sequencing technologies, integrative genomic analyses such as metabolomics and transcriptomics have made it possible to accurately identify metabolites and associated genes for plant organ coloration [ 18 ]. We describe transcriptomic and metabolomic changes in three bamboo cultivars to investigate coloration mechanisms.…”