采后茶青叶对振动力胁迫的生理响应  

Physiological Response of Postharvest Tea Leaves under Vibration Stress

作　　者：郝志龙[1] 林宏政[1] 徐邢燕 李鑫磊 俞晓敏 岳川[1] 孙云[1] 金心怡[1] HAO Zhilong;LIN Hongzheng;XU Xingyan;LI Xinlei;YU Xiaomin;YUE Chuan;SUN Yun;JIN Xinyi(Key Laboratory of Tea Science in Universities of Fujian Province,College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Zhejiang Commercial Technician Institute,Ningbo 315000,China;Tea Research Institute,Fujian Academy of Agricultural Sciences,Fuzhou 350013,China;Horticultural Plant Biology and Metabolomics Center,Haixia Institute of Science and Technology,Fujian Agricultural and Forestry University,Fuzhou 350002,China)

机构地区：[1]福建农林大学园艺学院,茶学福建省高校重点实验室,福建福州350002 [2]浙江商业技师学院,浙江宁波315000 [3]福建省农业科学院茶叶研究所,福建福州350013 [4]福建农林大学海峡联合研究院,园艺植物生物学及代谢组学中心,福建福州350002

出　　处：《食品科学》2023年第1期30-37,共8页Food Science

基　　金：财政部和农业农村部:国家现代农业产业技术体系项目(CARS-19);福建省现代农业(茶叶)产业技术体系专项(闽财指[2021]637号);福建农林大学科技创新发展基金项目(KFA17122A)。

摘　　要：摇青是乌龙茶品质形成的关键工序之一,其通过机械胁迫引起各种生物学效应,影响植物体内一系列生理生化变化,被广泛应用于花香红茶、花香白茶、花香绿茶等茶类的加工中以改善品质。为探明青叶响应机械力胁迫的生理变化,以采摘的‘铁观音’品种中开面三、四叶嫩梢为材料,经适度萎凋后进行自然摊放和振动力胁迫处理,研究青叶水分含量、光系统Ⅱ(photosystem Ⅱ,PS Ⅱ)参数、抗氧化酶活力及亚细胞结构的变化规律。结果表明:振动力胁迫30 min内青叶水分含量与自然摊放叶、萎凋叶间无显著差异(P>0.05),60 min时显著低于自然摊放叶和萎凋叶(P<0.05)。随着振动力胁迫时间延长,青叶青臭气增强,清香减弱;叶绿体和类囊体紧密而清晰的片层结构逐渐松散、变形、收缩、紊乱、瓦解,振动力胁迫处理5 min时淀粉粒数量明显增加,15 min时嗜锇颗粒数量明显增多,出现聚集。振动力胁迫青叶的PS Ⅱ实际光合效率Y(Ⅱ)和光化学猝灭系数qP随处理时间延长总体呈下降趋势,电子传递速率(electron transfer rate,ETR)随处理时间延长呈先降低后升高趋势,5 min和10 min时PS Ⅱ Y(Ⅱ)和ETR显著低于自然摊放(P<0.05);非调节性能量耗散的量子产额Y(NO)随振动力胁迫处理时间延长呈上升趋势,30 min时显著高于自然摊放叶(P<0.05)。振动力胁迫10 min青叶相对电导率显著高于自然摊放叶(P<0.05);青叶抗氧化酶中抗坏血酸过氧化物酶、脱氢抗坏血酸还原酶和谷胱甘肽还原酶活力在振动力胁迫处理5、10 min时高于自然摊放叶。综上,一定时间(30 min以内)的振动力胁迫对青叶水分含量影响不显著,但青气变浓,加剧青叶细胞膜系统损伤,使其透性提高,促进膜内可溶物渗出,造成相对电导率升高,类囊体降解,叶绿体严重受损,PS Ⅱ反应中心被破坏;此外,振动力胁迫能够通过提高活性氧代谢酶活性抵御机械胁迫对Shaking is one of the key processes contributing to the quality formation of oolong tea. As an abiotic stress factor, mechanical stress leads to a series of physiological and biochemical changes in plants through various biological effects, which has been widely used in the processing of scented black tea, scented white tea, scented green tea and other tea types to improve their quality. In order to ascertain the physiological changes of green tea leaves in response to mechanical stress, postharvest fresh shoots with 3–4 leaves from the tea cultivar ‘Tieguanyin’ were evaluated for changes in water content, photosystem Ⅱ(PS Ⅱ) parameters, antioxidant enzyme activities and subcellular structure under natural spreading or continuous vibration stress treatment after withering. Compared with naturally spread leaves and withered leaves, the water content in the leaves subjected to vibration stress was not significantly different within the first 30 min of vibration(P > 0.05) but was significantly lower at 60 min(P < 0.05). The green-grassy odor became stronger with increasing vibration time, the refreshing aroma became weaker, and the clear compact lamellar structures of the chloroplast and the thylakoid were gradually loosened, deformed, shrunk, and disrupted. The number of starch granules increased significantly at 5 min, and the number of osmiophilic granules increased significantly at 15 min, resulting in the formation of aggregates.The actual photosynthetic efficiency Y(Ⅱ) and photochemical quenching coefficient(qP) of PS Ⅱ generally showed a decreasing trend with increasing vibration time, and the electron transfer rate(ETR) declined initially and then rose. The Y(Ⅱ)and ETR at 5 and 10 min of vibration were significantly lower than those observed in naturally spread leaves(P < 0.05).The quantum yield Y(NO) of non-regulated energy dissipation increased with the prolongation of vibration stress treatment time, and was significantly higher than that of naturally spread leaves at 30 min(P < 0.05). The

关 键 词：乌龙茶 非生物胁迫 光系统Ⅱ参数 亚显微结构 抗氧化酶 

分 类 号：S571.1[农业科学—茶叶生产加工] TS272[农业科学—作物学]