Comparative Analysis of Two Flavonol Synthases from Different-Colored Onions Provides Insight into Flavonoid Biosynthesis

We isolated cDNAs encoding flavonol synthase (FLS) from the red onion “H6” (<i>AcFLS-H6</i>) and the yellow onion “Hwangryongball” (<i>AcFLS-HRB</i>). We found three amino acid variations between the two sequences. Kinetic analysis with recombinant proteins revealed that AcFLS-HRB exhibited approximately 2-fold higher catalytic efficiencies than AcFLS-H6 for dihydroflavonol substrates and that both proteins preferred dihydroquercetin to dihydrokaempferol. The expression patterns of flavonoid biosynthesis genes corresponded to the accumulation patterns of flavonoid aglycones in both onions. Whereas the other flavonoid biosynthesis genes were weakly expressed in the HRB sheath compared to that of H6, the expression of <i>FLS</i> was similar in both onions. This relatively enhanced <i>FLS</i> expression, along with the higher activity of AcFLS-HRB, could increase the quercetin production in the HRB sheath. The quercetin content was approximately 12-fold higher than the cyanidin content in the H6 sheath, suggesting that FLS has priority in the competition between FLS and dihydroflavonol 4-reductase (DFR) for their substrate dihydroquercetin

Metabolic Profiling in Chinese Cabbage (Brassica rapa L. subsp. pekinensis) Cultivars Reveals that Glucosinolate Content Is Correlated with Carotenoid Content

A total of 38 bioactive compounds, including glucosinolates, carotenoids, tocopherols, sterols, and policosanols, were characterized from nine varieties of Chinese cabbage (Brassica rapa L. subsp. pekinensis) to determine their phytochemical diversity and analyze their abundance relationships. The metabolite profiles were evaluated with principal component analysis (PCA), Pearson correlation analysis, and hierarchical clustering analysis (HCA). PCA and HCA identified two distinct varieties of Chinese cabbage (Cheonsangcheonha and Waldongcheonha) with higher levels of glucosinolates and carotenoids. Pairwise comparisons of the 38 metabolites were calculated using Pearson correlation coefficients. The HCA, which used the correlation coefficients, clustered metabolites that are derived from closely related biochemical pathways. Significant correlations were discovered between chlorophyll and carotenoids. Additionally, aliphatic glucosinolate and carotenoid levels were positively correlated. The Cheonsangcheonha and Waldongcheonha varieties appear to be good candidates for breeding because they have high glucosinolate and carotenoid levels

Data_Sheet_1_Proteomic Profiling and Epitope Analysis of the Complex α-, γ-, and ω-Gliadin Families in a Commercial Bread Wheat.XLSX

<p>Wheat gliadins are a complex group of proteins that contribute to the functional properties of wheat flour doughs and contain epitopes that are relevant for celiac disease (CD) and wheat-dependent exercise-induced anaphylaxis (WDEIA). In this study, we extracted ethanol-soluble gliadin fractions from flour of the Korean bread wheat cultivar Keumkang. Proteins were separated by 2-dimensional gel electrophoresis (2-DE) using a pI range of 6–11 in the first dimension and subjected to tandem mass spectrometry. α-, γ-, and ω-gliadins were identified as the predominant proteins in 31, 28, and one 2-DE spot, respectively. An additional six ω-gliadins were identified in a separate experiment in which a pI range of 3–11 was used for protein separation. We analyzed the composition of CD- and WDEIA-relevant epitopes in the gliadin sequences from Keumkang flour, demonstrating the immunogenic potential of this cultivar. Detailed knowledge about the complement of gliadins accumulated in Keumkang flour provides the background necessary to devise either breeding or biotechnology strategies to improve the functional properties and reduce the adverse health effects of the flour.</p

Presentation_1_Proteomic Profiling and Epitope Analysis of the Complex α-, γ-, and ω-Gliadin Families in a Commercial Bread Wheat.PPTX

<p>Wheat gliadins are a complex group of proteins that contribute to the functional properties of wheat flour doughs and contain epitopes that are relevant for celiac disease (CD) and wheat-dependent exercise-induced anaphylaxis (WDEIA). In this study, we extracted ethanol-soluble gliadin fractions from flour of the Korean bread wheat cultivar Keumkang. Proteins were separated by 2-dimensional gel electrophoresis (2-DE) using a pI range of 6–11 in the first dimension and subjected to tandem mass spectrometry. α-, γ-, and ω-gliadins were identified as the predominant proteins in 31, 28, and one 2-DE spot, respectively. An additional six ω-gliadins were identified in a separate experiment in which a pI range of 3–11 was used for protein separation. We analyzed the composition of CD- and WDEIA-relevant epitopes in the gliadin sequences from Keumkang flour, demonstrating the immunogenic potential of this cultivar. Detailed knowledge about the complement of gliadins accumulated in Keumkang flour provides the background necessary to devise either breeding or biotechnology strategies to improve the functional properties and reduce the adverse health effects of the flour.</p