茶园施肥模式对茶叶黄酮类及糖苷类代谢物含量的影响

Effects of fertilization patterns on flavonoids and glycoside metabolites in tea

【目的】研究施肥模式对茶叶生化成分含量和黄酮类及糖苷类代谢物累积的影响,为实现茶叶优质高产提供科学依据。【方法】田间试验设在四川茶树种植典型区域—雅安,试验连续进行了3年,设置不施肥(CK)、常量化肥(N 585 kg/hm^(2),TF)、有机肥替代25%化肥氮(OF)、减施25%氮肥(SF)4个处理。分析了不同处理茶叶主要品质成分含量,并基于非靶向代谢组学检测结果分析了黄酮类及糖苷类代谢物累积差异。【结果】与C K处理相比,T F、O F、S F处理茶氨酸、游离氨基酸含量分别提高了7.22%~13.40%、23.15%~25.50%,可溶性糖和茶多酚含量分别降低了8.17%~13.86%、6.08%~11.49%,表儿茶素、表没食子儿茶素、芸香苷等10种代谢物累积水平显著下降。与TF处理相比,SF处理茶氨酸、咖啡碱和水浸出物含量分别降低了5.45%、5.97%、8.91%,茶多酚、可溶性糖、游离氨基酸含量和酚氨比无显著差异;芍药素-3-O-葡萄糖苷、肉桂萜醇C1-19-葡萄糖苷、查耳酮樱花素等7种代谢物累积水平显著降低,川陈皮素、牡荆素-4'-O-α-L-吡喃鼠李糖苷、(S)-橙花醇-3-O-[a-L-鼠李糖吡喃醇-(1->2)-β-D-吡喃葡萄糖苷]和Ranupenin3-rutinoside等4种代谢物累积水平显著增加。与TF处理相比,OF处理茶叶咖啡碱含量降低了5.73%;茶氨酸、游离氨基酸、可溶性糖、茶多酚、水浸出物含量差异不显著;10种黄酮苷、2种黄酮、6种萜苷、5种甾体皂甙和2种脂酰苷共25种代谢物累积水平显著增加,以川陈皮素、飞燕草素-3-(6-对香豆酰基半乳糖苷)增幅较大,分别为2280.20%、1355.11%。4个处理相比,OF处理下有15种黄酮类及糖苷类代谢物累积水平显著高于CK、TF和SF处理。【结论】有机肥替代25%化肥氮降低了茶叶咖啡碱含量,提高了川陈皮素、飞燕草素、槲皮素、芹黄素、山奈酚、牡荆素等多种黄酮类代谢物和去氢大豆皂甙I、珠子参苷R2、孕甾烷甙等多种糖苷组分累积水平。减施25%氮肥降低了茶氨酸、咖啡碱、水浸出物含量和糖苷类代谢物(如杨梅酮-3-O-洋槐糖苷、芍药素-3-O-葡萄糖苷、肉桂萜醇C1-19-葡萄糖苷等)累积水平,对茶多酚、可溶性糖、游离氨基酸含量影响较小。有机肥替代部分化肥氮有利于茶叶黄酮类及糖苷类物质累积,单纯减少氮肥投入会降低茶叶品质。

【Objectives】This study examines the effects of fertilization patterns on the biochemical components and the accumulation of flavonoids and glycoside metabolites in tea leaves.【Methods】The 3-year field experiment was conducted in Ya’an which was a typical region of tea plant cultivation in Sichuan Provence,consisted of four treatments:no fertilization(CK),conventional chemical fertilizer input(N 585 kg/hm^(2)-TF),25%replacement of chemical fertilizer N with organic manure(OF),and reducing 25%of N supply(SF).The content changes in main quality components of tea leaves with different fertilization patterns were analyzed,as well as the accumulation variations of flavonoids and glycosidic metabolites based on the results of untargeted metabolomics.【Results】Compared with CK treatment,the contents of the anine and free amino acids in tea leaves under TF,OF,and SF treatments were significantly increased by 7.22%-13.40%,23.15%-25.50%,respectively,while soluble sugar and tea polyphenols contents decreased by 8.17%-13.86%,6.08%-11.49%,respectively.Concurrently,accumulation levels of 10 metabolites including epigallocatechin,epicatechin,and rutin decreased notably.Compared with TF treatment,the contents of theanine,caffeine and water-soluble extracts in tea leaves under SF treatment significantly decreased by 5.45%,5.97%,8.91%,respectively,while the content of tea polyphenols exhibited no significant difference as well as soluble sugar and free amino acid content.In addition,accumulation levels of 7 metabolites(e.g.peonidin 3-O-glucoside,cinncassiol C119-glucoside and chalconosakuranetin)decreased markedly,while that of 4 metabolites[e.g.nobiletin,vitexin 4'-O-α-L-rhamnopyranoside,(S)-Nerolidol 3-O-[a-L-rhamnopyranosyl-(1->2)-β-D-glucopyranoside]increased significantly.The contents of caffeine in tea leaves with OF treatment was 5.73%lower than that in TF.However,accumulation levels of 25 metabolites including 10 kinds of flavonoid glycosides,2 kinds of flavone,6 kinds of terpene glycosides,5 kinds of steroidal glycosides,and 2 kinds of fatty acyl glycosides compounds increased significantly,especially nobiletin and delphinidin 3-(6-p-coumaroylgalactoside)showed the higher increase at 2280.20%and 1355.11%,respectively.Among the four fertilization treatments,15 kinds of flavonoids and glycosides metabolites demonstrated higher accumulation levels in tea leaves with OF treatment compared with CK,TF,and SF treatments.【Conclusions】Replacing 25%of chemical fertilizer N with organic manure reduced the content of caffeine in tea leaves,and improved the accumulation levels of a variety of flavonoids metabolites(e.g.nobiletin,delphinidin,quercetin,apigenin,kaempferol,vitexin)and glycosylic components(e.g.dehydrosoyasaponin I,majonoside R2,balagyptin).Reducing 25%of N supply decreased the contents of theanine,caffeine and water-soluble extracts as well as the accumulation levels of glycosylic components(e.g.myricetin 3-O-robinobioside,peonidin 3-O-glucoside,cinncassiol C119-glucoside),and had less effect on tea polyphenols,soluble sugar,and free amino acid content.Partial substitution for chemical fertilizer N with organic manure is beneficial for the accumulation of flavonoids and glycosides in tea leaves.Onefold reduction of N input will reduce the quality of tea.