Metabolic networking in Brunfelsia calycina petals after flower opening

Abstract

Brunfelsia calycina flowers change colour from purple to white due to anthocyanin degradation, parallel to an increase in fragrance and petal size. Here it was tested whether the production of the fragrant benzenoids is dependent on induction of the shikimate pathway, or if they are formed from the anthocyanin degradation products. An extensive characterization of the events taking place in Brunfelsia flowers is presented. Anthocyanin characterization was performed using ultraperfomance liquid chromatography–quadrupole time of flight–tandem mass specrometry (UPLC-QTOF-MS/MS). Volatiles emitted were identified by headspace solid phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). Accumulated proteins were identified by 2D gel electrophoresis. Transcription profiles were characterized by cross-species hybridization of Brunfelsia cDNAs to potato cDNA microarrays. Identification of accumulated metabolites was performed by UPLC-QTOF-MS non-targeted metabolite analysis. The results include characterization of the nine main anthocyanins in Brunfelsia flowers. In addition, 146 up-regulated genes, 19 volatiles, seven proteins, and 17 metabolites that increased during anthocyanin degradation were identified. A multilevel analysis suggests induction of the shikimate pathway. This pathway is the most probable source of the phenolic acids, which in turn are precursors of both the benzenoid and lignin production pathways. The knowledge obtained is valuable for future studies on degradation of anthocyanins, formation of volatiles, and the network of secondary metabolism in Brunfelsia and related species.

Evolutionary correlations in flavonoid production across flowers and leaves in the Iochrominae (Solanaceae)

“…Finally, the white-flowered I. loxense was found to contain no anthocyanins. This correspondence between flower color and anthocyanin composition is similar to that observed in other Solanaceae (Bar-Akiva et al, 2010;Eich, 2008) and other clades of flowering plants (Wessinger and Rausher, 2012). However, this pattern is not universal.…”

Developmental Changes in the Metabolic Network of Snapdragon Flowers

“…Taken together, these results imply that the formation of volatile biosynthetic pathway intermediates and end-products is mainly regulated at the transcriptional level in snapdragon petals. Similarly, an induction of shikimate and phenylpropanoid pathway gene expression was observed after anthesis in Brunfelsia flowers, which produce phenylpropanoid volatiles [35]. In contrast to volatile biosynthetic pathways, genes involved in the anthocyanin formation were unchanged or down-regulated (Figure S1), suggesting that pigment accumulation in mature snapdragon flowers (Figure 1D) is primarily controlled postranscriptionally.…”

High temperature reduces apple fruit colour via modulation of the anthocyanin regulatory complex

“…2009). In Brunfelsia calycina (the yesterday–today–tomorrow plant), the flowers change colour from dark purple to white within 2–3 d after flower opening, but before senescence occurs (Bar‐Akiva et al . 2010).…”