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Article|13 Dec 2023|OPEN
Comprehensive dissection of variation and accumulation of free amino acids in tea accessions
Rong Huang1,2 , Zhihua Wang1 , Weiwei Wen2 , Mingzhe Yao1 , Haoran Liu1 , Fang Li1 , Shuran Zhang1 and Dejiang Ni2 , , Liang Chen,1 ,
1Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs; Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
2College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
*Corresponding author. E-mail: nidj@mail.hzau.edu.cn,liangchen@tricaas.com

Horticulture Research 11,
Article number: uhad263 (2024)
doi: https://doi.org/10.1093/hr/uhad263
Views: 27

Received: 11 Oct 2023
Accepted: 26 Nov 2023
Published online: 13 Dec 2023

Abstract

Free amino acids (FAAs) positively determine the tea quality, notably theanine (Thea), endowing umami taste of tea infusion, which is the profoundly prevalent research in albino tea genetic resources. Therefore, 339 tea accessions were collected to study FAAs level for deciphering its variation and accumulation mechanism. Interestingly, alanine (Ala) and Thea which had the highest diversity index (H′) value among three varieties of Camellia sinensis (L.) O. Kuntze were significantly higher than wild relatives (P < 0.05). The intraspecific arginine (Arg) and glutamine (Gln) contents in C. sinensis var. assamica were significantly lower than sinensis and pubilimba varieties. Moreover, the importance of interdependencies operating across FAAs and chlorophyll levels were highlighted via the cell ultrastructure, metabolomics, and transcriptome analysis. We then determined that the association between phytochrome interacting factor 1 (CsPIF1) identified by weighted gene co-expression network analysis (WGCNA) and Thea content. Intriguingly, transient knock-down CsPIF1 expression increased Thea content in tea plant, and the function verification of CsPIF1 in Arabidopsis also indicated that CsPIF1 acts as a negative regulator of Thea content by mainly effecting the genes expression related to Thea biosynthesis, transport, and hydrolysis, especially glutamate synthase (CsGOGAT), which was validated to be associated with Thea content with a nonsynonymous SNP by Kompetitive Allele-Specific PCR (KASP). We also investigated the interspecific and geographical distribution of this SNP. Taken together, these results help us to understand and clarify the variation and profile of major FAAs in tea germplasms and promote efficient utilization in tea genetic improvement and breeding.