Screening and Functional Analysis of Ethylene-responsive Genes Regulating Tomato Fruit Ripening and Respiration

doi:10.13560/j.cnki.biotech.bull.1985.2026-0003

Abstract

Abstract:

Objective This study is aimed to screen key factors responding to ethylene, regulating fruit ripening and associated with respiratory metabolism in tomato (Solanum lycopersicum) fruits. Their regulatory roles were clarified, which may provide a theoretical basis for deciphering the ethylene-mediated molecular network of tomato fruit ripening. Method Tomato cultivars were used as materials. Ethylene-responsive genes were identified by treating mature green fruits with ethylene/1-methylcyclopropene (1-MCP). Transcriptome sequencing was performed on the samples at five key stages of fruit ripening and respiratory climacteric. It was used to screen gene set with expression trends positively correlated with the respiratory peak. After integrating the two datasets, candidate genes were selected via Gene Ontology (GO) enrichment analysis and virus-induced gene silencing (VIGS) technology was used for functional verification. Result A total of 1 025 ethylene-responsive genes were identified. The intersection with 2 356 genes positively correlated with respiratory climacteric yielded 220 core genes, which were significantly enriched in respiratory metabolism pathways. Five candidate genes AOX1a, MPC1, NDB2, PCO2, and HIGD3 were selected. The VIGS silencing of each gene led to fruit ripening defects. Conclusion AOX1a, MPC1, NDB2, PCO2, and HIGD3 are key factors responding to ethylene signals, whose core function is to regulate tomato fruit ripening. They are associated with respiratory metabolism and may indirectly affect fruit respiration-related physiological processes.

Key words: tomato, fruit ripening, climacteric respiration, ethylene, transcriptome, VIGS

WANG Xiao-yi, LI Jin-yan, XING Xing, ZHU Hong-liang. Screening and Functional Analysis of Ethylene-responsive Genes Regulating Tomato Fruit Ripening and Respiration[J]. Biotechnology Bulletin, 2026, 42(3): 275-282.

Figures/Tables 5

Fig. 1 Dynamic changes of respiration rate and ethylene release amount in tomato fruitsA: Respiration rate and ethylene release of tomato fruit in different periods. B: Tomato fruit ripening process diagram.MG means mature green, Br means breaker

Fig. 2 Venn diagram of differentially expressed genes treated with ethylene and 1-MCP

Fig. 3 Transcriptome sample correlation analysis and differentially expressed gene clustering analysis of tomato (S. lycopersicum cultivar Ailsa Craig) fruitA: Sample correlation heat map. B: Cluster diagram of differentially expressed genes

Fig. 4 Screening of key ethylene-responsive genes regulating tomato fruit ripening and affecting fruit respirationA: Venn diagram of the intersection of ethylene-responsive genes and respiratory jump positive correlation genes. B: GO enrichment analysis of intersection genes. C: KEGG enrichment analysis of intersection genes. D: The expression trend of candidate genes in different stages of fruit ripening

Fig. 5 VIGS silencing phenotype and expression verification of candidate genesA: Fruit phenotype after VIGS treatment (Bar = 1 cm) . B: The relative expression of candidate genes in the red and yellow regions of fruit (different lowercase letters indicate a significant difference at P<0.05 level)

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