Open Access

ARTICLE

4-Hydroxy-2-Oxoglutaric Acid, A Key Metabolite Involved in Trypsin-Regulation of Arginine Metabolism in Hylocereus undatus during Storage

Bairu Li¹, Jingyu Jia¹, Hemin Wang¹, Jiaju Sun¹, Enyan Chen¹, Xin Li^1,2,3,*

1 College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, 471023, China
2 Henan Engineering Research Center of Food Microbiology, Luoyang, 471023, China
3 National Demonstration Center for Experimental Food Processing and Safety Education, Luoyang, 471000, China

* Corresponding Author: Xin Li. Email:

(This article belongs to the Special Issue: Multi-omics Approach to Understand Plant Stress Tolerance)

Phyton-International Journal of Experimental Botany 2024, 93(5), 885-900. https://doi.org/10.32604/phyton.2024.050450

Received 06 February 2024; Accepted 28 March 2024; Issue published 28 May 2024

Abstract

Trypsin, a novel superoxide scavenger, significantly enhances the storage quality of Hylocereus undatus (H. undatus). To elucidate the preservation mechanism of trypsin on H. undatus, a widely targeted metabolomic analysis, and transcriptomics analysis were conducted. Firstly, a total of 453 metabolites were identified, with organic acids and their derivatives constituting the largest proportion (25%). Amino acids and their metabolites, prominent among organic acids, were further analyzed. Among them, 73 metabolites were associated with amino acids, and 37 exhibited significant differences. The most enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was arginine biosynthesis (map00220), with polyamine metabolites showing the most pronounced differences, particularly spermine (FC = 1.7594). Compared with the control group, 4-hydroxy-2-oxoglutaric acid was significantly upregulated (FC = 2.117) in the process of spermine biosynthesis. Furthermore, the results of Gene Ontology (GO) and KEGG enrichment analysis of the H. undatus transcriptome profile revealed that trypsin treatment led to 187 differentially expressed genes associated with arginine. Both GO and KEGG analyses exhibited significant enrichment in the spermine biosynthetic process (GO:0006597) (map:00220) within the arginine biosynthesis pathway. Moreover, most enzymes and metabolites within the spermine biosynthesis pathway in H. undatus were upregulated. The results of the PPI network highlighted that ADC, SPDS, and SAMDC, among others, were pivotal proteins involved in trypsin-regulated arginine metabolism and spermine synthesis. This study revealed that trypsin could significantly delay postharvest senescence of H. undatus at room temperature. This effect might be attributed to trypsin triggering the synthesis of 4-hydroxy-2-oxoglutaric acid in the fruit peel, thereby promoting the biosynthesis of spermine and other polyamines.

---

Keywords

---

Supplementary Material

Supplementary Material File

---