CsGDH2.1 negatively regulates theanine accumulation in late-spring tea plants (Camellia sinensis var. sinensis)

作     者：Tingting Chen Jingzhen Ma Huiping Li Shijia Lin Chunxia Dong Yunxia Xie Xiaomei Yan Shupei Zhang Tianyuan Yang Xiaochun Wan Zhaoliang Zhang Tingting Chen;Jingzhen Ma;Huiping Li;Shijia Lin;Chunxia Dong;Yunxia Xie;Xiaomei Yan;Shupei Zhang;Tianyuan Yang;Xiaochun Wan;Zhaoliang Zhang

作者机构：State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityHefei 230036China 

出 版 物：《Horticulture Research》 (园艺研究（英文）)

年 卷 期：2023年第10卷第1期

页      面：240-248页

核心收录：

学科分类：0710[理学-生物学] 09[农学] 090203[农学-茶学] 0902[农学-园艺学] 

基　　金：This work was supported by grants from the National Natural Sci-ence Foundation of China(32072624) the National Key R&D Pro-gram of China(2021YFD1601101) Anhui Provincial Depart-ment of Human Resources and Social Security(2021LXC017) 

主　　题：spring infusion finding 

摘      要：Theanine,a unique and the most abundant non-proteinogenic amino acid in tea plants,endows tea infusion with the umami taste and anti-stress *** content in tea correlates highly with green tea *** content in new shoots of tea plants is high in mid-spring and greatly decreases in late ***,how the decrease is regulated is largely *** a genetic screening,we observed that a yeast mutant,glutamate dehydrolase 2(gdh2),was hypersensitive to 40 mM theanine and accumulated more *** result implied a role of CsGDH2s in theanine accumulation in tea ***,we identified the two homologs of GDH2,CsGDH2.1 and CsGDH2.2,in tea *** complementation assay showed that the expression of CsGDH2.1 in yeast gdh2 mutant rescued the theanine hypersensitivity and hyperaccumulation of this *** localization and tissue-specific expression showed CsGDH2.1 localized in the mitochondria and highly expressed in young ***,CsGDH2.1 expression was low in early spring,and increased significantly in late spring,in the new shoots of tea *** results all support the idea that CsGDH2.1 regulates theanine accumulation in the new ***,the in vitro enzyme assay showed that CsGDH2.1 had glutamate catabolic activity,and knockdown of CsGDH2.1 expression increased glutamate and theanine accumulation in the new shoots of tea *** findings suggested that CsGDH2.1-mediated glutamate catabolism negatively regulates theanine accumulation in the new shoots in late spring,and provides a functional gene for improving late-spring green tea quality.