Abstract:

The aim of this study was to further enrich the genomic information and uncover genes related to the synthesis and catabolism of S-alk（en）yl-L-cysteine sulfoxides（CSOs）. In the study，the content of three types of CSOs，namely S-allyl-L-cysteine sulfide（ACSO），S-methyl-L-cysteine sulfide（MCSO）， and S-propenyl-L-cysteine sulfide（PeCSO），was measured in 50 Chinese chives germplasm resources. Based on these result，two cultivars were selected for further analysis：‘Huanggezi’（HGZ），which exhibited the highest S-alk（en）yl-L-cysteine sulfoxide content，and‘Hami Goujiu’（HMGJ），which had the lowest S-alk（en）yl-L-cysteine sulfoxide content. Then，transcriptome sequencing was performed to compare gene expression differences between the two cultivars，and genes associated with the synthesis and catabolism of S-alk（en）yl-L-cysteine sulfoxides were identified. A total of 11 493 differentially expressed genes（DEGs）were identified，with 6 203 up-regulated，and 5 290 down-regulated. Gene Ontology（GO）enrichment analysis revealed that sulfur metabolic pathways related to S-alk（en）yl-L-cysteine sulfoxide biosynthesis were significantly enriched. Additionally，KEGG pathway analysis identified 122 enriched pathways，including those involved in sulfur metabolism，cysteine metabolism，and glutathione metabolism，which are closely associated with the synthesis and metabolism of S-alk（en）yl-L-cysteine sulfoxides. Through gene annotation，51 key genes involved in CSOs synthesis and catabolism were obtained. Among these，four flavin monooxygenase genes（AtuFMOs），two gamma glutamyl transpeptidase genes（AtuGGT），and seven alliinase genes（AtuALL）were found to be highly expressed in the‘Huanggezi’cultivar. These findings suggest that these genes may play a crucial role in regulating the synthesis and degradation of CSOs in Chinese chive.

Key words: Chinese chive, transcriptome, S-alk（en）yl-L-cysteine sulfoxides, syntheis and catabolism