Genomic Survey, Transcriptome, and Metabolome Analysis of Apocynum venetum and Apocynum hendersonii to Reveal Major Flavonoid Biosynthesis Pathways

Abstract

Apocynum plants, especially A. venetum and A. hendersonii, are rich in flavonoids. In the present study, a whole genome survey of the two species was initially carried out to optimize the flavonoid biosynthesis-correlated gene mining. Then, the metabolome and transcriptome analyses were combined to elucidate the flavonoid biosynthesis pathways. Both species have small genome sizes of 232.80 Mb (A. venetum) and 233.74 Mb (A. hendersonii) and showed similar metabolite profiles with flavonols being the main differentiated flavonoids between the two specie. Positive correlation of gene expression levels (flavonone-3 hydroxylase, anthocyanidin reductase, and flavonoid 3-O-glucosyltransferase) and total flavonoid content were observed. The contents of quercitrin, hyperoside, and total anthocyanin in A. venetum were found to be much higher than in A. hendersonii, and such was thought to be the reason for the morphological difference in color of A. venetum and A. hendersonii. This study provides valuable genomic and metabolome information for understanding of A. venetum and A. hendersonii, and lays a foundation for elucidating Apocynum genus plant flavonoid biosynthesis.

De novo transcriptome assembly and population genetic analyses of an important coastal shrub, Apocynum venetum L

“…So far, ISSR (Inter-Simple Sequence Repeat), AFLP and RAPD molecular markers have been developed for A. venetum [23,24,27]. In recent years, a number of transcriptome analyses have been conducted on A. venetum [20][21][22]. Using leaf material, we acquired a similar amount of venetum.…”

“…hendersonii, and some flavonoid components such as hyperoside have been identified as suitable chemical markers for the discrimination of the two species [34]. In a recent metabolome and transcriptome analyses of Apocynum, Gao et al [21] found that the flavonoid biosynthetic pathway is responsible for a considerable proportion of the diversity between A. venetum and A. hendersonii, and identified anthocyanin as the key component that determines the phenotypic diversity of the stem and leaf color of A. venetum and A.…”

“…hendersonii , and some flavonoid components such as hyperoside have been identified as suitable chemical markers for the discrimination of the two species [ 34 ]. In a recent metabolome and transcriptome analyses of Apocynum, Gao et al [ 21 ] found that the flavonoid biosynthetic pathway is responsible for a considerable proportion of the diversity between A. venetum and A. hendersonii , and identified anthocyanin as the key component that determines the phenotypic diversity of the stem and leaf color of A. venetum and A. hendersonii . In our KEGG analysis, 28,505 unigenes were clustered into 130 pathways, including the flavone and flavonol biosynthesis (ko00944), flavonoid biosynthesis (ko00941), isoflavonoid biosynthesis (ko00943), and anthocyanin biosynthesis (ko00942) pathways.…”

“…Simple sequence repeat (SSR) markers have been widely used in population genetic analysis and molecular marker-assisted breeding because of their high polymorphism, repeatability and codominant inheritance [18,19]. A number of transcriptome analyses have been conducted on A. venetum [20][21][22], while SSR markers have not yet been developed and used to evaluate the genetic diversity of natural A. venetum populations yet. Using RAPD (Random Amplification Polymorphic DNA) and AFLP (Amplified Fragment Length Polymorphism) markers, researchers have detected moderate to high levels of genetic diversity in A. venetum populations from Xinjiang and Inner Mongolia regions [23,24].…”

Characterization of the complete chloroplast genome of Apocynum venetum L. (Apocynaceae)

“… 2012 ; Gao et al. 2019 ). But despite its widely held medicinal value, genomic information about this plant is still lacking.…”