硫营养对不同抗性西瓜响应蔓枯病菌侵染的代谢组分析OA

Sulfur plays a crucial role in plant growth,development,and disease resistance.To explore the metabolic regu-latory mechanism of sulfur nutrition on watermelon with differing resistance in response to Didymella bryoniae infection,ultra-performance liquid chromatography-mass spectrometry(UPLC-MS)technology was used to analyze the metabolic changes in watermelon plants with distinct resistance levels at 24 hours post inoculation with Didymella bryoniae under sulfur nutrition treatment.Combined with principal component analysis(PCA),hierarchical clustering analysis(HCA),and KEGG pathway enrichment analysis,the differential metabolites and the key metabolic pathways were further eluci-dated.The results showed that sulfur treatment significantly altered the metabolic profiles of watermelon plants.A total of 183 differential metabolites were identified in resistant plants,which were mainly enriched in the phenylpropanoid biosyn-thesis and biosynthesis of type Ⅱ polyketide products pathways.In contrast,177 differential metabolites were detected in susceptible plants,and these metabolites were mainly enriched in the biosynthesis of secondary metabolites and biosynthe-sis of phenylpropanoids pathways.Further analysis revealed that the differential metabolites in resistant and susceptible plants were mainly concentrated in the phenylpropanoid biosynthesis pathway.Within this pathway,metabolites such as L-phenylalanine,coumarin,trans-anethole,and eugenol exhibited distinct accumulation patterns between resistant and sus-ceptible plants.It is speculated that these metabolites may serve as key players mediating sulfur-induced resistance against D.bryoniae in watermelon.Taken together,this study reveals the metabolic mechanism by which sulfur nutrition regulates the responses of resistant and susceptible watermelon to infection by the gummy stem blight pathogen.Specifi-cally,sulfur nutrition induces metabolic changes in plants,leading to the accumulation of phenylpropanoid compounds,which in turn enhances watermelon resistance to the disease.This work provides a valuable foundation for advancing the scientific control of gummy stem blight in watermelon.