Integrated Metabolomic and Transcriptomic Analysis Reveals Differential Flavonoid Accumulation and Its Underlying Mechanism in Fruits of Distinct Canarium album Cultivars

Abstract

Canarium album fruit has great potential to be consumed as a raw material not only for food but also medicine. The diverse active metabolites composition and content of C. album fruits greatly affect their pharmacological effects. However, up to now, there has been no report on the global metabolome differences among fruits from distinct C. album cultivars. In our present study, by using non-targeted metabolomics techniques, we identified 87 DAMs (differentially accumulated metabolites) including 17 types of flavonoids from fruits of four different C. album cultivars. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis revealed that the flavone and flavonol biosynthesis- and flavonoid biosynthesis-related DAMs were major factors determining their metabolome differences. Comparative transcriptomic analysis revealed that 15 KEGG pathways were significantly enriched by genes of the identified 3655 DEGs (differentially expressed genes) among different C. album cultivars. Consistent with the metabolome data, flavonoid biosynthesis-related DEGs, including eight key structural genes (such as FLS, CCoAOMT, CHI, C4H, DFR, LAR, and C3′H, etc.) and several regulatory transcription factor (TF) genes (including 32 MYBs and 34 bHLHs, etc.), were found to be significantly enriched (p < 0.01). Our study indicated that the differential expression of flavonoid biosynthesis-related genes and accumulation of flavonoids played dominant roles in the various metabolome compositions of fruits from different C. album cultivars.

Integrated Analysis of Widely Targeted Metabolomics and Transcriptomics Reveals the Effects of Transcription Factor NOR-like1 on Alkaloids, Phenolic Acids, and Flavonoids in Tomato at Different Ripening Stages

“…The genes associated with flavonoid biosynthesis are mainly classified into structural and regulatory genes [41]for instance, CHS, FLS, F3H, F3 H, C4H, etc. C4H plays an important role in flavonoid biosynthesis [42][43][44]. Correlation analysis showed that C4H at all three ripening stages positively regulated flavonoids including luteolin, hesperetin, homoeriodictyol, phloretin, butin, aromadendrin, naringenin chalcone, and pinobanksin.…”

The composition of phenolic compounds in Chinese olive (Canarium album L.) cultivars and their contribution to the anti-inflammatory properties of the cultivars

“…The “Tan xiang” cultivar exhibited significantly higher levels of flavones, flavanols, and their derivatives than the other two cultivars ( p < 0.05). Although genistin was detected ( 8 ), its limited quantity precluded quantification.…”

“…As one of the 110 medicinal foods in China, Chinese olive contains higher free phenolic levels (300 mg/100 g fresh weight) than grapes, apples, pears, and other fruits and also ranks first among 68 Chinese medicinal materials in terms of phenolic content ( 6 ). Despite being rich in FPs ( 7 , 8 ), there is a paucity of studies comparing the PCs profiles of different Chinese olive cultivars, especially the bound phenolic fraction.…”

Chinese olive (Canarium album Rauesch.): a critical review on its nutritional value, phytochemical composition, health benefits, and practical applications

“…The varieties with rough flesh and light taste had a significantly higher total lignin content compared to the varieties with a crisp and strong taste (2.34—fold higher) and the varieties with sweet and non-astringent fruit (4.18—fold higher). Among them, the difference in ellagic acid, hyperoside, ferulic acid, and sinapic acid contents may be an important factor contributing to the fruit flavor differences ( Lai et al, 2022 ). In addition, lighting conditions and stress are major factors affecting plants’ phenolic content, directly affecting phenolic compounds metabolism in plants.…”

“…Chinese olive is nutrient-rich and is a delicious and naturally healthy food. Chinese olives have been consumed for a long time as a fruit having a sweet and sour taste and a lasting aftertaste ( Lai et al, 2022 ). At the same time, it is also commonly used for food seasoning.…”