Abstract:

To explore the effects of different harvest maturity on internal quality of upper leaves and metabolomics of tobacco， Yunyan 87 was used as the experimental material， and the leaves were sampled with SPAD value of 30~35 （BM1）， 25~30 （BM2）， 20~25 （BM3）， 15~20 （BM4）. The effects of different harvest maturity on the agronomic traits， chemical composition coordination， sensory quality and metabolomics of upper leaves were analyzed. The results showed that the upper leaves of BM3 treatment had better coordination of chemical components and the highest sensory evaluation score. A total of 230 differential metabolites were screened from 4 treatments， mainly including organic acids， alkaloids， sugars， amino acids， alcohols and nucleosides. Bioinformatics analysis showed that L-tryptophan， chlorogenic acid， palmitoleic acid， concanavalin， creatine， sorbitol， trigonelline， α-linolenic acid， glyceric acid， traumatic acid， choline， matairesinol， deoxyinosine， rutin， L-phenylalanine， guanine， L-proline， L-methionine， glucaric acid， nicotine， oleic acid， L-serine， flavic acid， L-glutamic acid， syringic acid， eugenol and tryptophan might be the key metabolites during the maturation of upper tobacco leaves. Differential metabolites were significantly enriched in pathways such as amino acid metabolism， nucleotide metabolism， carbohydrate metabolism， vitamin metabolism and lipid metabolism. Among them， glycine， serine and threonine metabolism， phenylpropanoid biosynthesis， alanine， aspartic acid and glutamic acid metabolism pathways played an important regulatory role in the formation of oil and aroma substances during tobacco leaf maturation.

Key words: tobacco leaf, metabolomics, maturity, differential metabolites

摘要：

为探究不同采收成熟度对上部叶的内在质量和代谢组学的影响，以云烟87为试验材料，采收叶片SPAD值分别为30~35（BM1）、25~30（BM2）、20~25（BM3）、15~20（BM4）的烤烟上部叶，研究不同采收成熟度对上部叶农艺性状、化学成分协调性、感官质量以及代谢组学的影响。结果显示，BM3处理上部叶的化学成分协调性较好，感官评吸分数最高。4种处理共筛选出230种差异代谢物，主要是有机酸类、生物碱类、糖类、氨基酸类、醇类和核苷类等。生物信息学分析表明，差异代谢物中的L-色氨酸、绿原酸、棕榈油酸、刀豆氨酸、肌酸、山梨醇、葫芦巴碱、α-亚麻酸、甘油酸、创伤性酸、胆碱、马泰树脂醇、脱氧肌苷、芸香苷、L-苯丙氨酸、鸟嘌呤、L-脯氨酸、L-蛋氨酸、葡糖二酸、尼古丁、油酸、L-丝氨酸、黄氧酸、L-谷氨酸、丁香酸、丁香酚、色胺酸等可能是上部烟叶成熟过程中较关键的代谢物。差异代谢物显著富集在氨基酸代谢、核苷酸代谢、碳水化合物代谢、维生素代谢和脂质代谢等通路中，其中甘氨酸、丝氨酸和苏氨酸的代谢，苯丙烷类生物合成，丙氨酸、天冬氨酸和谷氨酸代谢等通路在烟叶成熟过程中油分和香气物质的形成起重要调控作用。

关键词: 烟叶, 代谢组学, 成熟度, 差异代谢物