Integrated Metabolomic and Transcriptomic Analysis Reveals the Flavonoid Regulatory Network by Eutrema EsMYB90

Abstract

Flavonoids are representative secondary metabolites with different metabolic functions in plants. Previous study found that ectopic expression of EsMYB90 from Eutrema salsugineum could strongly increase anthocyanin content in transgenic tobacco via regulating the expression of anthocyanin biosynthesis genes. In the present research, metabolome analysis showed that there existed 130 significantly differential metabolites, of which 23 metabolites enhanced more than 1000 times in EsMYB90 transgenic tobacco leaves relative to the control, and the top 10 of the increased metabolites included caffeic acid, cyanidin O-syringic acid, myricetin and naringin. A total of 50 markedly differential flavonoids including flavones (14), flavonols (13), flavone C-glycosides (9), flavanones (7), catechin derivatives (5), anthocyanins (1) and isoflavone (1) were identified, of which 46 metabolites were at a significantly enhanced level. Integrated analysis of metabolome and transcriptome revealed that ectopic expression of EsMYB90 in transgenic tobacco leaves is highly associated with the prominent up-regulation of 16 flavonoid metabolites and the corresponding 42 flavonoid biosynthesis structure genes in phenylpropanoid/flavonoid pathways. Dual luciferase assay documented that EsMYB90 strongly activated the transcription of NtANS and NtDFR genes via improving their promoter activity in transiently expressed tobacco leaves, suggesting that EsMYB90 functions as a key regulator on anthocyanin and flavonoid biosynthesis. Taken together, the crucial regulatory role of EsMYB90 on enhancing many flavonoid metabolite levels is clearly demonstrated via modulating flavonoid biosynthesis gene expression in the leaves of transgenic tobacco, which extends our understanding of the regulating mechanism of MYB transcription factor in the phenylpropanoid/flavonoid pathways and provides a new clue and tool for further investigation and genetic engineering of flavonoid metabolism in plants.

Flavonoids Accumulation in Fruit Peel and Expression Profiling of Related Genes in Purple (Passiflora edulis f. edulis) and Yellow (Passiflora edulis f. flavicarpa) Passion Fruits

“…Therefore, these two enzymes are likely to be the key enzymes affecting the metabolism of flavonoids in purple and yellow passion fruit peel (Figure 9). PAL and C4H were positively correlated with flavonoid content in tobacco [53], while CHS expression was significantly positively correlated with anthocyanin content in pomegranate [54]. Flavonoid related synthetic genes showed early and late expression peaks in grape [55], Vaccinium myrtillus [49] and wild apple (Malus Sylvestris L.) [56].…”

Integrative Metabolome and Transcriptome Analysis Reveals the Regulatory Network of Flavonoid Biosynthesis in Response to MeJA in Camelliavietnamensis Huang

“…The central pathway of flavonoid biosynthesis is conserved in plants [ 8 ]. Up to now, enzymes involved in flavonoid biosynthesis have been well characterized in Vitis vinifera [ 9 ], Zea mays L. [ 10 ], Arabidopsis thaliana L. [ 11 ], and Fagopyrum tataricum [ 12 ], and so on.…”

“…The flavonoid synthesis pathway begins with the catalysis of the precursor phenylalanine by phenylalanine ammonia lyase ( PAL ), followed by the production of the chalcone by trans cinnamate 4-monooxygenase ( C4H ) [ 6 ]. Chalcone synthase ( CHS ) is the first committed enzyme in the biosynthesis of all flavonoids [ 8 ], which catalyzes p-coumaroyl-CoA to generate naringenin chalcone or phloretin [ 6 ]. The high expression of the CHS gene enhances flavonoid accumulation in Perilla frutescens leaves by metabolomic and transcriptomic analysis [ 14 ].…”

“…The high expression of the CHS gene enhances flavonoid accumulation in Perilla frutescens leaves by metabolomic and transcriptomic analysis [ 14 ]. Chalcone isomerase ( CHI ) catalyzes the isomerization of naringenin chalcone to flavanone naringenin [ 8 ]. Then flavanone naringenin acts as the substrate to produce flavones (such as flavanones, dihydroflavonols, and anthocyanins) by the action of various enzymes which include flavonoid 3-hydroxylase ( F3H ), flavonoid 3’-hydroxylase ( F3’H ), flavonoid 3’5’-hydroxylase ( F3’5’H ), flavonol synthase ( FLS ), anthocyanidin synthase ( ANS ), anthocyanin reductase ( ANR ) and so on [ 6 , 15 ].…”

Integrated Metabolomic-Transcriptomic Analysis Reveals Diverse Resource of Functional Ingredients From Persimmon Leaves of Different Varieties

“…Persimmon leaf tea has been used as a pleasant, functional beverage and an effective, traditional herbal remedy for a long time ( Chen et al, 2009 ; Chang et al, 2019 ), but how to increase the content of functional compounds and improve the quality and flavor of persimmon leaf tea by screening the varieties/cultivars rich in flavonoid, mineral, or aroma compounds are largely unexplored. In recent years, integrative metabolomic-transcriptomic analysis has been extensively applied to reveal the relationship between the contents of secondary metabolites and their corresponding differentially expressed genes (DEGs; Zhou et al, 2019 , 2022 ; Wan et al, 2020 , 2021 ; Zhang et al, 2020 ; Qi et al, 2021 ; Wang et al, 2021 ).…”