Chen Yuzhen, Wang Feng, Wu Zhidan, Jiang Fuying, Yu Wenquan, Yang Jie, Chen Jiaming, Jian Guotai, You Zhiming, Zeng Lanting
Tea Research Institute, Fujian Academy of Agricultural Sciences, No. 104 Pudang Road, Xindian Town, Jin'an District, Fuzhou 350012, China.
National Agricultural Experimental Station for Soil Quality, No. 1 Hutouyang Road, Shekou Town, Fu'an 355015, China.
Metabolites. 2021 Mar 2;11(3):146. doi: 10.3390/metabo11030146.
As a main agronomic intervention in tea cultivation, nitrogen (N) application is useful to improve tea yield and quality. However, the effects of N application on the formation of tea quality-related metabolites have not been fully studied, especially in long-term field trials. In this study, a 10-year field experiment was conducted to investigate the effect of long-term N application treatments on tea quality-related metabolites, their precursors, and related gene expression. Long-term N application up-regulated the expression of key genes for chlorophyll synthesis and promoted its synthesis, thus increasing tea yield. It also significantly increased the contents of total free amino acids, especially l-theanine, in fresh tea leaves, while decreasing the catechin content, which is conducive to enhancing tea liquor freshness. However, long-term N application significantly reduced the contents of benzyl alcohol and 2-phenylethanol in fresh tea leaves, and also reduced ()-nerolidol and indole in withered leaves, which were not conducive to the formation of floral and fruity aroma compounds. In general, an appropriate amount of N fertilizer (225 kg/hm) balanced tea yield and quality. These results not only provide essential information on how N application affects tea quality, but also provide detailed experimental data for field fertilization.
作为茶叶种植中的一项主要农艺措施，施氮有助于提高茶叶产量和品质。然而，施氮对茶叶品质相关代谢产物形成的影响尚未得到充分研究，尤其是在长期田间试验中。本研究通过为期10年的田间试验，探究长期施氮处理对茶叶品质相关代谢产物、其前体物质及相关基因表达的影响。长期施氮上调了叶绿素合成关键基因的表达并促进其合成，从而提高了茶叶产量。它还显著增加了鲜叶中总游离氨基酸的含量，尤其是茶氨酸，同时降低了儿茶素含量，这有利于提升茶汤的鲜爽度。然而，长期施氮显著降低了鲜叶中苯甲醇和2-苯乙醇的含量，也降低了萎凋叶中（）-橙花叔醇和吲哚的含量，这不利于花香和果香类香气化合物的形成。总体而言，适量施氮（225 kg/hm）可平衡茶叶产量和品质。这些结果不仅为施氮如何影响茶叶品质提供了重要信息，也为田间施肥提供了详细的实验数据。
