Zhou Xiaolong, Wang Yuehui, Liang Huixing, Chen Shuai, Ding Wenping, Zhuang Kun
College of Modern Industry of Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
Key Laboratory of Bulk Grain and Oil Deep Processing, Ministry of Education, Wuhan 430023, China.
Food Chem (Oxf). 2025 May 28;10:100264. doi: 10.1016/j.fochms.2025.100264. eCollection 2025 Jun.
Watermelon seeds are readily accepted even after selenium enrichment, thereby potentially helping meet daily selenium requirements of adults. However, no existing studies have elucidated the molecular-level metabolic changes in watermelon seeds induced by selenium enrichment. In this study, UPLC-MS/MS was employed to identify and quantify metabolite alterations in watermelon seeds. A total of 1036 metabolites were identified, and 81 differentially expressed metabolites (DEMs) being screened out. Gene identification and expression analysis were conducted using the Illumina NovaSeq 6000 platform. A total of 18,686 genes were identified, and 999 differentially expressed genes (DEGs) were screened out. Joint omics analysis revealed that DEMs and DEGs were enriched in 25 pathways, primarily involving flavonoid biosynthesis and amino acid metabolism. Genes like PAL, 4CL, CYP73A, and CHS were the key genes for the biosynthesis of flavonoids under selenium treatment, resulting in a significant decrease in the expression level of chlorogenic acid in the pathway. In the amino acid metabolism pathway, genes such as AGXT2, glnA, speE, and thrC played crucial roles, causing significant alterations in the expression levels of metabolites such as L-Alanine, Threonine, and Tryptophan in the pathway. This study provides a theoretical basis for developing watermelon seeds with both selenium-enrichment function and balanced nutrition. The selenium enrichment process can be improved by regulating the expression levels of key genes such as PAL and AGXT2, and the amino acid composition can also be regulated.
即使经过富硒处理，西瓜籽仍很容易被接受，因此有可能有助于满足成年人每日的硒需求。然而，目前尚无研究阐明富硒处理对西瓜籽分子水平代谢变化的影响。在本研究中，采用超高效液相色谱-串联质谱法（UPLC-MS/MS）对西瓜籽中的代谢物变化进行鉴定和定量。共鉴定出1036种代谢物，筛选出81种差异表达代谢物（DEM）。使用Illumina NovaSeq 6000平台进行基因鉴定和表达分析。共鉴定出18686个基因，筛选出999个差异表达基因（DEG）。联合组学分析表明，DEM和DEG富集于25条通路，主要涉及黄酮类生物合成和氨基酸代谢。在硒处理下，苯丙氨酸解氨酶（PAL）、4-香豆酸辅酶A连接酶（4CL）、细胞色素P450 73A（CYP73A）和查尔酮合酶（CHS）等基因是黄酮类生物合成的关键基因，导致该通路中绿原酸的表达水平显著下降。在氨基酸代谢通路中，丙氨酸-乙醛酸转氨酶2（AGXT2）、谷氨酰胺合成酶（glnA）、精胺合成酶（speE）和苏氨酸合成酶（thrC）等基因发挥着关键作用，导致该通路中L-丙氨酸、苏氨酸和色氨酸等代谢物的表达水平发生显著变化。本研究为开发具有富硒功能和营养均衡的西瓜籽提供了理论依据。通过调节PAL和AGXT2等关键基因的表达水平，可以改进富硒过程，同时也可以调节氨基酸组成。
