Dynamic Metabolomics and Transcriptomics Analyses for Characterization of Phenolic Compounds and Their Biosynthetic Characteristics in Wheat Grain

Abstract

Phenolic compounds are important bioactive phytochemicals with potential health benefits. In this study, integrated metabolomics and transcriptomics analysis was used to analyze the metabolites and differentially expressed genes in grains of two wheat cultivars (HPm512 with high antioxidant activity, and ZM22 with low antioxidant activity) during grain development. A total of 188 differentially expressed phenolic components, including 82 phenolic acids, 81 flavonoids, 10 lignans, and 15 other phenolics, were identified in the developing wheat grains, of which apigenin glycosides were identified as the primary flavonoid component. The relative abundance of identified phenolics showed a decreasing trend with grain development. Additionally, 51 differentially expressed phenolic components were identified between HPm512 and ZM22, of which 41 components, including 23 flavonoids, were up-regulated in HPm512. In developing grain, most of the identified differentially expressed genes involved in phenolic accumulation followed a similar trend. Integrated metabolomics and transcriptomics analysis revealed that certain genes encoding structural proteins, glycosyltransferase, and transcription factors were closely related to metabolite accumulation. The relatively higher accumulation of phenolics in HPm512 could be due to up-regulated structural and regulatory genes. A sketch map was drawn to depict the synthetic pathway of identified phenolics and their corresponding genes. This study enhanced the current understanding of the accumulation of phenolics in wheat grains. Besides, active components and their related genes were also identified, providing crucial information for the improvement of wheat's nutritional quality.

Antioxidant Capacity and Profiles of Phenolic Acids in Various Genotypes of Purple Wheat

“…Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acid levels. Also, some identified differentially expressed genes, such as flavonol synthase (TraesCS1A02G221200 and TraesCS1A02G320000), and glycosyltransferase genes (TraesCS7D02G198300 and TraesCS1D02G301700) may play an important role in phenolics biosynthesis [ 39 ].…”

Influence of lactic acid fermentation on the phenolic profile, antioxidant activities, and volatile compounds of black chokeberry (Aronia melanocarpa) juice

“…It has been proven that phenolic compounds can transfer hydrogen atoms or donate electrons to free radicals, thus possessing remarkable antioxidant activity (Ma et al., 2022). Thus, the antioxidant activities were investigated and exhibited based on DPPH, ABTS, and reducing power capacity, as shown in Table 2.…”

Integrative metabolome and transcriptome profiling provide insights into elucidation of the synthetic mechanisms of phenolic compounds in Yunnan hulled wheat (Triticum aestivum ssp. yunnanense King)

“…Transcriptome sequencing and profiling Total RNA was extracted from YHW whole grains during development stages as previously described, 46 and a total of 24 transcriptome libraries were sequenced and analyzed by Metware Biotechnologies Co. Ltd by HISAT2 (2.1.0) aligned raw RNA sequenced reads with the reference genome sequence (https:// www.wheatgenome.org/) of wheat. 46 Thereafter rMATS (4.0.2) was used to compare the high-quality reads with the spliced transcriptome, StringTie (1.3.3b) was used to assemble the aligned reads and calculate the gene expression levels (fragments per kilobase of transcript per million fragments mapped, FPKM), and DESeq2 (1.22.1) and clusterProfiler (v3.10.1) were applied to annotate and enrich the differentially expressed genes (DEGs).…”

“…45,46 There is a relatively comprehensive understanding of the PC biosynthetic pathways in model crops such as Arabidopsis, rice and corn. 47 While the PC biosynthetic pathways have also been well reported in modern wheat varieties, 20,46 related research for the grains of ancient and semiwild wheat varieties is currently very limited. In addition, to date, there have been only a few reports on the transcriptome and metabolomics research of phenolics in modern wheat varieties, including the synthesis pathways of PAs, 20 anthocyanins 48 and phenolics 46 during grain development.…”

“…47 While the PC biosynthetic pathways have also been well reported in modern wheat varieties, 20,46 related research for the grains of ancient and semiwild wheat varieties is currently very limited. In addition, to date, there have been only a few reports on the transcriptome and metabolomics research of phenolics in modern wheat varieties, including the synthesis pathways of PAs, 20 anthocyanins 48 and phenolics 46 during grain development. However, the biosynthesis and regulatory mechanisms of phenolics during grain development in different lines of YHW have not received attention.…”