茶树γ-氨基丁酸代谢途径对早期茶尺蠖取食为害的响应  

Response ofγ-Aminobutyric Acid Metabolic Pathway in Tea Plants to Early Infestation of Ectropis obliqua

作　　者：孙娟 陈慧 刘关华 张瀚 黄福印 王玉玺 王诺 保德孟 施江[2,4] 戴伟东 陈健[1] 付建玉 SUN Juan;CHEN Hui;LIU Guanhua;ZHANG Han;HUANG Fuyin;WANG Yuxi;WANG Nuo;BAO Demeng;SHI Jiang;DAI Weidong;CHEN Jian;FU Jianyu(College of Life Sciences and Medicine,Zhejiang Sci-Tech University,Hangzhou 310018,China;Tea Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310008,China;Key Laboratory of Tea Quality and Safety Control,Ministry of Agriculture and Rural Affairs,Hangzhou 310008,China;Key Laboratory of Tea Biology and Resources Utilization,Ministry of Agriculture and Rural Affairs,Hangzhou 310008,China)

机构地区：[1]浙江理工大学生命科学与医药学院,浙江杭州310018 [2]中国农业科学院茶叶研究所,浙江杭州310008 [3]农业农村部茶叶质量安全控制重点实验室,浙江杭州310008 [4]农业农村部茶树生物学与资源利用重点实验室,浙江杭州310008

出　　处：《茶叶科学》2024年第5期816-830,共15页Journal of Tea Science

基　　金：中国农业科学院科技创新工程(CAAS-ASTIP-2014-TRICAAS)。

摘　　要：茶尺蠖(Ectropis obliqua Prout)为害会诱导茶树释放大量挥发性代谢物,这些代谢物作为重要信号物质在趋避害虫或吸引天敌方面的研究已被广泛报道,但茶尺蠖为害对茶树叶片中非挥发性代谢物质空间变化的影响及其作用尚不清楚。以茶树叶片为材料,限制茶尺蠖仅在叶尖部取食,再采集叶尖部、叶中部、叶基部3个位点组织,基于超高效液相色谱-四极杆轨道阱质谱(UHPLC-Q-Exactive/MS)的分析方法对这3个位点组织的非挥发性代谢物质进行鉴定和分析。结果表明,与空白对照和机械损伤相比,茶尺蠖为害可诱导6种二聚儿茶素类、3种氨基酸类(包括γ-氨基丁酸)、1种黄酮和黄酮苷类、1种酚酸类共11种差异代谢物。与空白对照相比,茶尺蠖为害后,茶树叶片3个位点的γ-氨基丁酸相对含量均明显增加,在叶中部和叶基部均增加了1.99倍,且γ-氨基丁酸生物合成途径中的关键基因在这3个位点均上调表达。茶尺蠖为害后,在叶片叶尖部和叶基部,γ-氨基丁酸的相对含量与其前体物质谷氨酸的相对含量呈显著正相关(P<0.05)。茶尺蠖取食添加了0.2、0.5、2.0 mg·g^(-1)γ-氨基丁酸的人工饲料后,其体质量和体长均显著小于对照组(P<0.05)。本研究表明,γ-氨基丁酸代谢途径在茶树抵御茶尺蠖为害的早期防御反应中发挥了重要作用,为进一步揭示茶树的生化抗性机制奠定基础。Tea geometrid(Ectropis obliqua Prout)infestation induces tea plants to release massive amounts of volatile organic compounds(VOCs),which are widely reported as important chemical cues that either repel the pests or attract their enemies.However,the spatial variations and the roles of the non-volatile metabolites in tea leaves infested by the tea geometrids are confusing.Taking tea leaves as materials,the feeding of E.obliqua was limited at the leaf tip,and then the tissues at the leaf tip,middle and base were collected.The non-volatile metabolites of the tissues at the three sites were identified and analyzed by ultra-high performance liquid chromatography-quadrupole orbitrap mass spectrometry(UHPLC-Q-Exactive/MS).The results demonstrate that compared with the blank control and mechanical injury tea leaves,tea geometrids induced 11 differential metabolites,including six dimeric catechins,three amino acids(includingγ-aminobutyric acid),one flavonoid and flavonoid glycoside,and one phenolic acid compound.After the infestation of the tea geometrids,the relative contents ofγ-aminobutyric acid at the three sites in tea leaves were significantly increased compared to the blank control tea leaves,and increased by 1.99-fold in the middle and base of leaves.In addition,the key genes involved in theγ-aminobutyric acid biosynthetic pathway were upregulated at all three sites of tea leaves.There was a significant positive correlation between the relative content ofγ-aminobutyric acid and the relative content of glutamic acid(P<0.05).When the tea geometrids were fed with artificial diet supplemented with 0.2 mg·g^(-1),0.5 mg·g^(-1) and 2.0 mg·g^(-1)γ-aminobutyric acid,their body weight and length were both significantly decreased compared with the control(P<0.05).The present study indicates that the inhibitory neurotransmitterγ-aminobutyric acid plays a pivotal role in the early defense response against tea geometrids,which will shed light on the biochemical resistance mechanism of the tea plants.

关 键 词：茶树 茶尺蠖 Γ-氨基丁酸 空间变化 

分 类 号：S571.1[农业科学—茶叶生产加工] S435.711[农业科学—作物学]