文献类型： 外文期刊

作者： Liang, Xiaojie ¹ ; An, Wei ² ; Li, Yuekun ² ; Qin, Xiaoya ² ; Zhao, Jianhua ² ; Su, Shuchai ¹ ;

作者机构： 1.Beijing Forestry Univ, Coll Forestry, Key Lab Forest Silviculture & Conservat, Minist Educ, Beijing, Peoples R China

2.Wolfberry Sci Res Inst, Ningxia Acad Agr & Forestry Sci, Natl Wolfberry Engn Res Ctr, Yinchuan, Peoples R China

关键词： wolfberry fruits; nitrogen application rate; pick batch; nutrient composition; metabolomics

期刊名称：FRONTIERS IN PLANT SCIENCE （ 影响因子：5.6； 五年影响因子：6.8 ）

ISSN： 1664-462X

年卷期： 2024 年 15 卷

页码：

收录情况： SCI

摘要： Lycium barbarum L., commonly known as wolfberry, is not only a traditional Chinese medicine but also a highly nutritious food. Its main nutrients include L. barbarum polysaccharide, flavonoid polyphenols, carotenoids, alkaloids, and other compounds, demonstrating its wide application value. This study investigated the effects of nitrogen application on the accumulation of the main nutrients and metabolites in wolfberry fruits under three different nitrogen application rates, namely, N1 (20% nitrogen (N) reduction, 540 kgha-2), N2 (medium N, 675 kgha-2), and N3 (20% nitrogen increase, 810 kgha-2,which is a local conventional nitrogen application amount.). Additionally, due to continuous branching, blossoming, and fruiting of wolfberry plants during the annual growth period, this research also explored the variation in nutritional composition among different harvesting batches. The contents of total sugar and polysaccharide in wolfberry fruit were determined by Fehling reagent method and phenol-sulfuric acid method, respectively;The content of betaine in fruit was determined by high-performance liquid chromatography,and the flavonoids and carotene in the wolfberry fruits were determined by spectrophotometry. Analysis of data over three consecutive years revealed that as nitrogen application increased, the total sugar content in wolfberry fruits initially decreased and then increased. The levels of L. barbarum polysaccharides, total flavonoids, and total carotenoids initially increased and then decreased, while the betaine content consistently increased. Different picking batches significantly impacted the nutrient content of wolfberry fruits. Generally, the first batch of summer wolfberry fruits had greater amounts of total sugar and flavonoids, whereas other nutrients peaked in the third batch. By employing a broadly targeted metabolomics approach, 926 different metabolites were identified. The top 20 differentially abundant metabolites were selected for heatmap generation, revealing that the contents of L-citrulline, 2-methylglutaric acid, and adipic acid increased proportionally to the nitrogen gradient. Conversely, the dibutyl phthalate and 2, 4-dihydroxyquinoline contents significantly decreased under high-nitrogen conditions. The remaining 15 differentially abundant metabolites, kaempferol-3-O-sophorosid-7-O-rhamnoside, trigonelline, and isorhamnosid-3-O-sophoroside, initially increased and then decreased with increasing nitrogen levels. Isofraxidin, a common differentially abundant metabolite across all treatments, is a coumarin that may serve as a potential biomarker for wolfberry fruit response to nitrogen. Differentially abundant metabolites were analyzed for GO pathway involvement, revealing significant enrichment in metabolic pathways and biosynthesis of secondary metabolites under different nitrogen treatments. In conclusion, a nitrogen application of 675 kgha-2, 20% less than the local farmers' actual application, was most beneficial for the quality of four-year-old Ningqi 7 wolfberry fruits. Consumers who purchase wolfberry-dried fruit for health benefits should not consider only the first batch of summer wolfberry fruits. These results offer a broader perspective for enhancing the quality and efficiency of the wolfberry industry.