What question did this study set out to answer?

This study aims to understand the proteomic and metabolomic changes during the ripening of Hovenia dulcis pseudofruit.

April 27, 2026Open Access

Building Hovenia dulcis pseudofruit quality from proteomic and metabolomic perspectives

Key Points

This study aims to understand the proteomic and metabolomic changes during the ripening of Hovenia dulcis pseudofruit.
Utilized multi-omic analyses to identify proteins and metabolites involved in pseudofruit development.
Conducted multivariate analysis to categorize ripening into three distinct phases: defense, metabolic transition, and sensory ripening.
Investigated the correlation between key enzymes and sensory attributes using Pearson correlations.
Identified 496 proteins, with 222 differentially expressed, highlighting key roles of malate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase.
Confirmed that high energy metabolism is essential during ripening, linked to photosynthetic pathways such as RuBisCO and Photosystems I and II.
Found that changes in volatile compounds like 2-heptanol and pigment measurements drive the transition from chemical defense to sensory ripening.

Abstract

Hovenia dulcis Thunb. (Japanese grape tree) pseudofruit exhibits a period of growth of 180 days, with maturation initiated between 120 and 150 days after anthesis (DAA). Effective ripening occurs 150 DAA, characterized by intense softening, pectic solubilization and starch-sugar conversion. Multi-omic analysis identified 496 proteins, with 222 being differentially expressed. Significant highlights included energy metabolism (Malate Dehydrogenases, Glyceraldehyde-3-phosphate Dehydrogenase, Pyruvate Kinase) and photosynthetic pathways (Ribulose-1,5-bisphosphate Carboxylase/Oxygenase, Photosystems I and II), indicating that ripening demands a high energy supply. Multivariate analysis stratified the development into three phases: chemical defense (S1-S2), metabolic transition (S3-S6), and sensory ripening (S7). The Variable Importance in Projection (VIP) score and Principal Component 1 (PC1) loadings confirmed that the transition is governed by changes in volatile compounds (2-heptanol), respiratory physiology, density, and Hue angle, with a central role for malate dehydrogenase. Pearson correlations revealed a coordinated system in which central metabolism (Glyceraldehyde-3-phosphate Dehydrogenase, Triose Phosphate Isomerase) is coupled with ethylene signaling (S-adenosylmethionine Synthetase) and antioxidant defenses (Superoxide Dismutase, Catalase, and Peroxiredoxin 2). It is concluded that H. dulcis development is sustained by a strategic proteometabolic network that redirects the investment from protective biomolecules toward the specialization of sensory attributes, defining the final quality of the pseudofruit. Highlights • Three phases (S1-S7) define the shift from defense to sensory ripening. • Multiomics identifies 222 DEP, highlighting MDH, GAPDH, and PK hubs. • RuBisCO and PSI/II peak to sustain high metabolic demand during ripening. • VIP Score confirms 2-heptanol and Hue angle as key transition drivers. • Co-regulation links glycolysis (TPI) to ethylene (SAMS) and antioxidant defense.

Building Hovenia dulcis pseudofruit quality from proteomic and metabolomic perspectives

Key Points

Abstract

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