Multi-omics analysis revealing the taste characteristics and formation mechanism of Ocimum

Abstract

Ocimum, a plant of significant economic value, finds extensive applications in the food, spice, and pharmaceutical industries. This study integrated sensory evaluation, metabolomics, and transcriptomics to systematically analyze taste differentiation in four Ocimum accessions (G126, G081, G096, G124). Standardized quantitative descriptive analysis (QDA) revealed distinct taste profiles: G126 (O. basilicum) exhibited high sweetness and low bitterness, G081 (O. kilimandscharicum) showed prominent minty notes, G096 (O. gratissimum) demonstrated intense piquancy, and G124 (O. gratissimum) displayed unique numbness. UPLC-MS/MS-based metabolomics identified 2275 metabolites, with key taste-metabolite correlations established: N-acetyl-tryptophan positively correlated with sweetness, N-isobutyl decanamide with numbness, flavonoids (particularly flavanones) with bitterness, and terpenoids (monoterpenoids) with minty perception. Transcriptomics uncovered 18 bitterness-associated DEGs (PAL, 4CL, C4H, CHS) in flavonoid pathways and 8 minty-linked DEGs (DXS, ispG, ispH, TPS) in terpenoid biosynthesis. Crucially, we constructed an integrated regulatory network linking sensory attributes, key metabolites, and genetic determinants. Our specific conclusions are: Non-sugar metabolite N-acetyl-tryptophan is the primary sweetness contributor in Ocimum; Genotype-specific expression of terpenoid/flavonoid pathway genes drives minty/bitter taste divergence; N-isobutyl decanamide represents a novel chemosensory marker for numbness. These findings provide molecular targets for flavor optimization in pharmaceutical and food applications of Ocimum.