油茶果采后不同处理种仁代谢组学分析Metabolomics analysis of kernels of Camellia oleifera fruit treated with different methods after harvest

旨在寻找油茶果最佳采后处理方式，为其后续研究奠定基础，采用液相色谱-质谱联用法（LC-MS/MS）对油茶果采后不同处理〔不处理（F8）、堆沤处理（FC）、去壳摊晒（NS）、带壳摊晒（WS）〕10、30 d种仁代谢物进行测定，并用相关软件对代谢产物进行分析。结果表明：鉴定出1 107种特征代谢物，其中正离子模式和负离子模式下鉴定的代谢物数量分别为763种和344种，代谢物主要为脂类和类脂分子（277种），苯丙烷类和聚酮类（193种），有机酸及其衍生物（172种），类苯（97种），有机杂环化合物（94种），有机氧化合物（84种），核苷、核苷酸和类似物（33种）；通过比较差异代谢物不饱和脂肪酸发现，去壳摊晒处理30 d（NS2） vs 10 d（NS1）比较组中检测到亚油酸、顺式-9-十六碳烯酸、8（9）-环氧-5Z，11Z，14Z-二十碳三烯酸、亚麻酸、蓖麻油酸、9,10-环氧十八碳烯酸共6种不饱和脂肪酸，且都表达上调；对差异代谢物进行富集分析发现，主要参与的代谢途径有苯丙氨酸代谢、类黄酮生物合成、甘油磷脂代谢、甘油酯代谢、玉米素生物合成、植物次生代谢产物的生物合成、谷胱甘肽代谢、氨基酸的生物合成、次生代谢产物的生物合成。综上，油茶果采后最佳处理方式为去壳摊晒30 d。In order to find the optimal postharvest treatment of Camellia oleifera fruit, and lay the foundation for subsequent research, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine the metabolites of the kernels of different postharvest treatments of Camellia oleifera fruit 〔without treatment （F8）, composting treatment（FC） , sun dried without shell （NS）, and sun dried with shell（WS）〕 for 10 d and 30 d, and relevant software was used to analyze the metabolites. The results showed that a total of 1 107 characteristic metabolites were identified, with 763 and 344 metabolites identified in the positive and negative ion modes, respectively. The main metabolites were lipids and lipid-like molecules( 277 kinds), phenylpropanoids and polykettides (193 kinds), organic acids and derivatives(172 kinds), benzenoids (97 kinds), organoheterocyclic compounds (94 kinds), organic oxygen compounds (84 kinds), nucleosides, nucleotides and analogues(33 kinds). By comparison of the unsaturated fatty acid of differential metabolites, six unsaturated fatty acids, namely linoleic acid, cis-9-hexadecenoic acid, 8 (9) - epoxy-5Z, 11Z, 14Z-eicosatrienoic acid, linolenic acid, ricinolic acid, 9,10-epoxy-octadecenoic acid, were detected in 30 d (NS2) and 10 d (NS1) of the sun dried without shell treatment, and their expressions were up-regulated. The enrichment analysis of differential metabolites results showed that the main metabolic pathways included phenylalanine metabolism, flavonoid biosynthesis, glycerol phospholipid metabolism, glycerol ester metabolism, zeatin biosynthesis, plant secondary metabolites biosynthesis, glutathione metabolism, amino acid biosynthesis, and secondary metabolites biosynthesis. Overall, the best postharvest treatment of Camellia oleifera fruit is sun dried without shell treatment for 30 d.