Metabolomics and Transcriptomics Reveal that Diarylheptanoids Vary in Amomum tsao-ko Fruit Development

Amomum tsao-ko is an important
spice
and medicinal plant that has received extensive attention in recent
years for its high content of bioactive constituents with the potential
for food additives and drug development. Diarylheptanoids are major
and characteristic compounds in A. tsao-ko; however, the biochemical and molecular foundation of diarylheptanoids
in fruit is unknown. We performed comparative metabolomics and transcriptomics
studies in the ripening stages of A. tsao-ko fruit. The chemical constituents of fruit vary in different harvest
periods, and the diarylheptanoids have a trend to decrease or increase
with fruit development. GO enrichment analysis revealed that plant
hormone signaling pathways including the ethylene-activated signaling
pathway, salicylic acid, jasmonic acid, abscisic acid, and response
to hydrogen peroxide were associated with fruit ripening. The biosynthetic
pathways including phenylpropanoid, flavonoids, and diarylheptanoids
biosynthesis were displayed in high enrichment levels in ripening
fruit. The molecular networking and phytochemistry investigation of A. tsao-ko fruit has isolated and identified 10 diarylheptanoids
including three new compounds. The candidate genes related to diarylheptanoids were obtained by coexpression
network analysis and phylogenetic analysis. Two key genes have been
verified to biosynthesize linear diarylheptanoids. This integrative
approach provides gene regulation and networking associated with the
biosynthesis of characteristic diarylheptanoids, which can be used
to improve the quality of A. tsao-ko as food and medicine.