Transcriptome and chemical analyses revealed the mechanism of flower color formation in Rosa rugosa

Abstract

Rosa rugosa is a famous Chinese traditional flower with high ornamental value and well environmental adapt ability. The cultivation of new colorful germplasms to improve monotonous flower color could promote its landscape application. However, the mechanism of flower color formation in R. rugosa remains unclear. In this study, combined analyses of the chemical and transcriptome were performed in the R. rugosa germplasms with representative flower colors. Among the identified anthocyanins, cyanidin 3,5-O-diglucoside (Cy3G5G) and peonidin 3,5-O-diglucoside (Pn3G5G) were the two dominant anthocyanins in the petals of R. rugosa. The sum content of Cy3G5G and Pn3G5G was responsible for the petal color intensity, such as pink or purple, light- or dark- red. The ratio of Cy3G5G to Pn3G5G was contributed to the petal color hue, that is, red or pink/purple. Maintaining both high relative and high absolute content of Cy3G5G may be the precondition for forming red-colored petals in R. rugosa. Cyanidin biosynthesis shunt was the dominant pathway for anthocyanin accumulation in R. rugosa, which may be the key reason for the presence of monotonous petal color in R. rugosa, mainly pink/purple. In the upstream pathway of cyanidin biosynthesis, 35 differentially expressed structural genes encoding 12 enzymes co-expressed to regulate the sum contents of Cy3G5G and Pn3G5G, and then determined the color intensity of petals. RrAOMT, involved in the downstream pathway of cyanidin biosynthesis, regulated the ratio of Cy3G5G to Pn3G5G via methylation and then determined the color hue of petals. It was worth mentioning that significantly higher delphinidin-3,5-O-diglucoside content and RrF3’5’H expression were detected from deep purple-red-flowered 8-16 germplasm with somewhat unique and visible blue hue. Three candidate key transcription factors identified by correlation analysis, RrMYB108, RrC1, and RrMYB114, might play critical roles in the control of petal color by regulating the expression of both RrAOMT and other multiple structural genes. These results provided novel insights into anthocyanin accumulation and flower coloration mechanism in R. rugosa, and the candidate key genes involved in anthocyanin biosynthesis could be valuable resources for the breeding of ornamental plants in future.

Integrated Transcriptome and Metabolome Analyses Reveal Bamboo Culm Color Formation Mechanisms Involved in Anthocyanin Biosynthetic in Phyllostachys nigra

“…These transcription factors are capable of forming the MBW complex, which has been shown to play a critical role in anthocyanin synthesis in a wide range of plant species [44,45]. The regulation of anthocyanins by MYB has been studied in Arabidopsis [46], Rosa rugose [47], Tulipa gesneriana [48], etc. According to the phylogenetic tree, PnMYB1 is grouped in the same subgroup as AtMYB3 and exhibits a comparable role in restricting anthocyanin synthesis by repressing phenylalanine metabolism [28].…”

Integrative analysis of transcriptome and metabolome profiling reveal coloration molecular mechanisms in four rapeseed petals with different color

“…Understanding the internal regulation mechanism of color formation and the pigments variation and transformation in rapeseed petals could provide an important theoretical basis for cultivating and improving new colorful rapeseed varieties [14,15].The coloration regulation mechanism in rapeseed petal is a complex progress, yet only a few genes involved in ehe coloration formation have been found. The expression of ANS, FLS1 and MYB4 in white rapeseed petals was lower than that in rose red petals, and CHS, F3H, ANS and MYB4 were more highly expressed in rose petals, compared to white petals [16]. Comparing with yellow or white flowers, the structural genes related to anthocyanin synthesis and three key transcription factor genes BnaMYBL2, BnaA07, PAP2 and BnaTT8 in apricot-red and pink rape petals were sharply up-regulated [17].…”

Combined Metabolomic and Transcriptomic Analysis Reveals Candidate Genes for Anthocyanin Accumulation in Ginkgo biloba Seed Exocarp

“…Anthocyanins are a class of natural water-soluble pigments with important physiological activities, belonging to polyphenolic flavonoid substances, which are widely found in seed plants. Due to their complex and diverse structural modifications, various anthocyanin derivatives are formed to cause changes in plant color [7][8][9], which can cause changes in the color of flowers, leaves, fruits, seeds and other tissues and organs [10][11][12][13][14][15][16][17][18][19][20]. They can also improve the ability of plants to resist adverse environments.…”