Metabolomic and transcriptomice analyses of flavonoid biosynthesis in apricot fruits

Temporal changes in total flavonoid content (TFC), composition, free radical scavenging activity and metabolism-related gene expression of three Prunus humilis cultivars with distinctively different fruit colors were investigated in this study. The highest fruit TFCs of all three cultivars were observed at the initial sampling stage (young-fruit stage, YFS), which then declined gradually until fruit ripening. The dark-red-fruited cultivar ‘Jinou 1’ had the highest TFC, followed by the yellow-red-fruited cultivar ‘Nongda 3’ and the yellow-fruited cultivar ‘Nongda 5’. Thirteen flavonoid compounds were found in the three cultivars by using high-performance liquid chromatography (HPLC), and the content of most flavonoid compounds gradually decreased throughout the fruit-ripening process, with the exception of cyanidin-3-O-glucoside (C3G). C3G, as the main anthocyanin in P. humilis fruits, increased drastically during the fruit-coloring process of cultivars ‘Jinou 1’ and ‘Nongda 3’, while it was not detected in the developing fruits of cultivar ‘Nongda 5’. The antioxidant activity assay (DPPH, FRAP and ABTS) revealed that fruits of all three cultivars at YFS also had the highest antioxidant activities, and cultivar ‘Jinou 1’ had the highest antioxidant activities. Correlation analysis revealed that the antioxidant activities were significantly positively correlated with the TFCs and contents of the main compounds such as catechin, proanthocyanidin B1 and phloretin-2′,4-O-diglucoside (p < 0.01). Moreover, gene expression analysis showed that the flavonoid biosynthetic genes had different expression patterns in the three cultivars. The expression levels of ChCHS, ChCHI, ChF3H, ChDFR, ChLDOX and ChUFGT increased gradually with fruit ripening in cultivar ‘Jinou 1’, while all flavonoid-related genes in cultivar ‘Nongda 5’ decreased gradually during fruit development. The results from our study could significantly contribute to the deeper understanding of flavonoid accumulation mechanisms in P. humilis fruits and also help facilitate the targeted cultivar development and the utilization as a functional food of this fruit species.

Section: Discussioncontrasting

confidence: 99%

Temporal Changes in Flavonoid Components, Free Radical Scavenging Activities and Metabolism-Related Gene Expressions during Fruit Development in Chinese Dwarf Cherry (Prunus humilis)

Han,

Zhang,

Liu

et al. 2023

“…Supportively, Oude Griep et al have demonstrated that the ability of fruits and vegetables to treat coronary heart diseases varies depending on their color [46]. Furthermore, these findings corroborate with reports in other fruit crops [12,14,47]. All DAMs in pairwise comparisons between groups were identified, providing fundamental data for in-depth exploration of the variation in bioactive compounds among the four different colored BMPs.…”

Section: Discussionsupporting

confidence: 75%

Integrative Metabolome and Transcriptome Analyses Reveal the Pericarp Coloration Mechanisms in Bitter Melon (Momordica charantia L.)

Yang,

Li,

et al. 2024

Pericarp colors are critical agronomic traits that affect the quality and economic values of fruits. Although a diversity of bitter melon pericarp (BMP) colors is available, the fruit pigmentation mechanisms remain elusive. Hence, this study aimed to unveil the key metabolites and molecular mechanisms underlying variation in BMP coloration through integrative metabolomics and transcriptomics analyses of four differently colored genotypes, including K1102 (grayish orange), 262 (grayish yellow), 1392 (very soft green), and K115 (dark grayish cyan). The four BMPs exhibited significant metabolite profile and transcriptional differences, as over 112 and 1865 DAMs (differentially accumulated metabolites) and DEGs (differentially expressed genes), respectively, were identified. The variation in the content of six anthocyanins, including malvidin 3-O-glucoside, petunidin 3-O-glucoside, rosinidin O-hexoside, cyanidin, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside, and pelargonidin 3-O-beta-D-glucoside, might be the major driving factor of BMP color changes. Notably, malvidin 3-O-glucoside, rosinidin O-hexoside, and petunidin 3-O-glucoside are the dominant pigments in K115, while carotenoids and other flavonoids may contribute to other colors. Candidate flavonoid structural and regulatory (MYBs, NACs, MADSs, bHLHs, and bZIPs) genes were identified. Of them, gene13201 (anthocyanin reductase), gene8173 (polyphenol oxidase), gene2136 (NAC43), gene19593 (NAC104), and gene15171 (tetrapyrrole-binding protein) might play essential roles in K115 pericarp color development. Our findings deepen our understanding of BMP pigmentation and provide fundamental resources for higher-valued bitter melon breeding perspectives.

“…On the other hand, the phenylalanine metabolic pathway offers an alternate route for the biosynthesis of specific isoflavonoids and flavonol compounds [20,21]. The biosynthesis of flavonoid compounds is tightly regulated by various biosynthetic enzymes and genes, including PAL, 4CL, CHS, FLS, and F3 ′ H [22,23]. In our study, we employed ELISA and qPCR techniques to evaluate the influence of humic acid on these pivotal biosynthetic enzymes involved in flavonoid compound production.…”

Section: Discussionmentioning

confidence: 99%

The Effect and Potential Mechanism of Fulvic Acid on Flavonoids in Lemon Leaves

Ren,

Yang,

Dai

et al. 2024

Citrus limon (L.) Burm. f. is a horticultural crop known for its abundance of valuable secondary metabolites, including flavonoids, which are found in its fruits and leaves. Our previous research has shown that treating C. limon with fulvic acid (FA) can enhance the levels of vitamin C, total acid, total sugar, total flavonoids, and phenols in its fruits as well as the volatiles and total flavonoids in its leaves. In this current study, we established a method to analyze eight specific flavonoids in lemon leaves and evaluated the impact of irrigation with FA on the content of these flavonoids over a six-month period using HPLC-DAD/MS analysis. Moreover, we investigated the potential mechanisms of FA through ELISA and q-PCR methods. The results indicated that FA increased the contents of four flavonoids, namely, isoorientin, eriocitrin, vitexin, and rutin, and promoted the activity and gene expression of phenylalanineammonialyase (PAL), 4-coumaric acid coenzyme A ligase (4CL), chalcone synthase (CHS), flavonoid 3′-hydroxylase (F3′H), and flavonol synthase (FLS). Furthermore, the relationship between flavonoid content and the activities of biosynthetic enzymes was analyzed using orthogonal partial least squares discriminant analysis (OPLS-DA), which revealed a positive correlation between seven flavonoid levels and the activity of five biosynthetic enzymes under FA treatment.