农业与食品化学杂志:农科院茶叶所阮建云研究组揭示春茶品质差
近日，国际期刊《JouRNAl of Agricultural and food Chemistry》杂志上在线发表了中国农业科学院茶叶研究所茶树生理与营养创新团队揭示春季不同时期绿茶品质代谢成分波动成因。 刘健伟博士和张群峰博士为共同第一作者，阮建云研究员为通讯作者。
春茶品质与采摘时间有着重要的联系，通常早春采摘的春茶品质好于晚春采摘的春茶，但对其成因还缺少深入研究。该团队通过采集春季不同时期(4月1 日、4月15日、4月28日)茶树新梢、成熟叶样品，利用二维气相色谱-飞行时间质谱、超高效液相色谱-四极杆飞行时间质谱分析茶树的初级和次级代谢物。研究发现，后期春茶主要氨基酸如茶氨酸、谷氨酸、谷氨酰胺的含量显著降低，而碳水化合物、类黄酮(黄烷醇、槲皮素及其糖苷)合成、三羧酸循环和光呼吸等代谢显著增强，说明新梢碳氮代谢变化深刻地影响了不同时期春茶的品质。代谢组学分析进一步发现成熟叶的代谢在此期间也发生了显著变化，向新梢转移、维持春季新梢活性的氮、碳在后期减弱，引起茶树新梢代谢发生变化，导致春季茶叶品质波动。该成果为今后提出栽培调控技术提供了研究基础。
原文链接：
Metabolomic Analyses Reveal Distinct Change of Metabolites and Quality of Green Tea during the Short Duration of a Single Spring Season
原文摘要：
The sensory quality of green tea changes greatly within a single spring season, but the mechanism is not clearly elucidated. Young shoots of the early, middle, and late spring season were subjected to metabolite profiling using gas chromatography–time-of-flight mass spectrometry (TOF/MS) and ultraperformance liquid chromatography–quadrupole–TOF/MS. Multivariate analyses revealed largely different metabolite phenotypes in young shoots among different periods. The contents of amino acids decreased, whereas carbohydrates, flavonoids and their glycosides, tricarboxylic acid cycle, and photorespiration pathways were strongly reinforced in the late spring season, which were well reflected in the sensory quality of made teas. Metabolomic analyses further demonstrated distinct variations of metabolite phenotypes in mature leaves. The results suggested that the fluctuation of green tea quality in the spring season was caused by changes of metabolite phenotypes in young shoots, which was likely related to the remobilization of carbon and nitrogen reserves from mature leaves.
作者：阮建云
