In recent years, Yunnan's large leaf tea and ancient tea resources have attracted much attention, while there are relatively few reports on the research of small leaf tea resources. Shilixiang, a distinctive small leaf tea resource in Yunnan, possessed unique quality and a long drinking history. Spatial transcriptome technology, an emerging gene expression analysis technique, has not been previously applied to tea resources according to current literature. The gene characterization and spatial regulation mechanism of the tender buds of Shilixiang were researched by spatial transcriptome sequencing technology in this study. The results show that 13 clusters of different cell types in the tender bud cells were identified by a spot clustering analysis and the spatial transcriptome map was constructed. The expression positions of clusters during the two developmental stages of the bud were different and spatial heterogeneity was observed from this analysis. Further exploration involved the identification of differential genes in various cell type clusters, with a focus on stress response and growth and development regulation. Representative stress responsive genes included LOC114312694, LOC114319171, LOC114320792, LOC114287723, LOC114284011 and LOC114289235. Meanwhile, representative growth and development genes included LOC114263486, LOC114320821, LOC114292779, LOC114321117, and LOC114286858. A spatial distribution map illustrated the high expression of these stress response and growth development genes in young leaves, indicating their crucial role in the early stage of tender bud development. Further GO and KEGG enrichment analysis reveal that the differential genes in the tender buds of Shilixiang are associated with multiple important pathways. These pathways included translation, jasmonic acid signal regulation, calcium ion binding, and plant hormone signal transduction, all of which are closely linked to the growth and development of tea plants. The results of this study provided a solid scientific foundation for understanding the developmental biology of Shilixiang. Additionally, they provided a new perspective for exploring other tea resources.
[1] 程琳, 郝艳林, 曹思睿, 等. 茶树基因组研究进展[J]. 信阳师范学院学报(自然科学版), 2021, 34(4): 606-613.
Cheng L, Hao Y L, Cao S R, et al.Advances in genome research of tea plant[J]. Journal of Xinyang Normal University (Natural Science Edition), 2021, 34(4): 606-613.
[2] Xia E H, Zhang H B, Sheng J.The tea tree genome provides insights into tea flavor and independent evolution of caffeine biosynthesis[J]. Molecular Plant, 2017, 10(6): 866-877.
[3] Wei C L, Yang H, Wang S B, et al.Draft genome sequence of Camellia sinensis var. sinensis provides insights into the evolution of the tea genome and tea quality[J]. PNAS, 2018, 115(18): E4151-E4158.
[4] Xia E H, Tong W, Wu Q, et al.Tea plant genomics: achievements, challenges and perspectives[J]. Horticulture Research, 2020, 7: 7. doi: 10.1038/s41438-019-0225-4.
[5] Xia E H, Tong W, Hou Y, et al.The reference genome of tea plant and resequencing of 81 diverse accessions provide insights into its genome evolution and adaptation[J]. Molecular Plant, 2020, 13(7): 1013-1026.
[6] Chen J D, Zheng C, Ma J Q, et al.The chromosome-scale genome reveals the evolution and diversification after the recent tetraploidization event in tea plant[J]. Horticulture Research, 2020, 7: 63. doi: 10.1038/s41438-020-0288-2.
[7] Wang X C, Feng H, Chang Y X, et al.Population sequencing enhances understanding of tea plant evolution[J]. Nature Communications, 2020, 11: 4447. doi: 10.1038/s41467-020-18228-8.
[8] Lin P, Wang K L, Wang Y P, et al.The genome of oil-camellia and population genomics analysis provide insights into seed oil domestication[J]. Genome Biology, 2022, 23: 14. doi: 10.1186/s13059-021-02599-2.
[9] Xiang P, Zhu Q F, Zhang L H, et al.Integrative analyses of transcriptome and metabolome reveal comprehensive mechanisms of epigallocatechin-3-gallate (EGCG) biosynthesis in response to ecological factors in tea plant (Camellia sinensis)[J]. Food Research International, 2023, 166: 112591. doi: 10.1016/j.foodres.2023.112591.
[10] Zhang Y R, Fu J M, Zhou Q Y, et al.Metabolite profiling and transcriptome analysis revealed the conserved transcriptional regulation mechanism of caffeine biosynthesis in tea and coffee plants[J]. Journal of Agricultural and Food Chemistry, 2022, 70(10): 3239-3251.
[11] Zheng Y C, Wang P J, Chen X J, et al.Integrated transcriptomics and metabolomics provide novel insight into changes in specialized metabolites in an albino tea cultivar (Camellia sinensis (L.) O. Kuntz)[J]. Plant Physiology and Biochemistry, 2021, 160: 27-36.
[12] Chang L, Jing L, Li Y L, et al.A spatiotemporal atlas of organogenesis in the development of orchid flower[J]. Nucleic Acids Research, 2022, 50(17): 9724-9737.
[13] 李方东. 茶树转录组组装评估与多组学生物信息平台开发[D]. 合肥: 安徽农业大学, 2021.
Li D F.Evaluation of tea transcriptome assembly and development of multi-group student information platform [D]. Hefei: Anhui Agricultural University, 2021.
[14] 刘芳芳, 刘文祥, 郑伟, 等. 茶树NF-Y基因家族鉴定及非生物胁迫下的表达分析[J]. 江苏农业科学, 2023, 51(5): 81-93.
Li F F, Liu W X, Zheng W, et al.Identification of NF-Y gene family in tea tree and expression analysis under abiotic stresses[J]. Jiangsu Agricultural Sciences, 2023, 51(5): 81-93.
[15] Shi C Y, Yang H, Wei C L, et al.Deep sequencing of the Camellia sinensis transcriotome revealed candidate genes for major metabolic pathways of tea-specific compounds[J]. BMC Genomics, 2011, 12: 131. doi: 10.1186/1471-2164-12-131.
[16] Qiu H J, Zhang X L, Zhang Y J, et al.Depicting the genetic and metabolic panorama of chemical diversity in the tea plant[J]. Plant Biotechnology Journal, 2024, 22(4): 1001-1016.
[17] Lei X G, Li H Y, Li P P, et al.Genome-wide association studies of biluochun tea plant populations in Dongting mountain and comprehensive identification of candidate genes associated with core agronomic traits by four analysis models[J]. Plants, 2023, 12(21): 3179. doi: 10.3390/plants12213719.
[18] Wang X C, Zhao Q Y, Ma C L, et al.Global transcriptome profiles of Camellia sinensis during cold acclimation[J]. BMC Genomics, 2013, 14: 415. doi: 10.1186/1471-2164-14-415.
[19] Qiu H J, Zhu X, Wan H L, et al.Parallel metabolomic and transcriptomic analysis reveals key factors for quality improvement of tea plants[J]. Journal of Agricultural and Food Chemistry, 2020, 68(19): 5483-5495.
[20] Giacomello S, Salmén F, Terebieniec B K, et al.Spatially resolved transcriptome profiling in model plant species[J]. Nature Plants, 2017, 3: 17061. doi: 10.1038/nplants.2017.61.
[21] Moreno-Villena J J, Zhou H R, Gilman I S, et al. Spatial resolution of an integrated C4+CAM photosynthetic metabolism[J]. Science Advances, 2022, 8(31): 2349. doi: 10.1126/sciadv.abn2349.
[22] Song X H, Guo P R, Xia K K, et al.Spatial transcriptomics reveals light-induced chlorenchyma cells involved in promoting shoot regeneration in tomato callus[J]. PNAS, 2023, 120(38): e2310163120. doi: 10.1073/pnas.2310163120.
[23] Yang X L, Poelmans W, Grones C, et al.Spatial transcriptomics of a lycophyte root sheds light on root evolution[J]. Current Biology, 2023, 33(19): 4069-4084.
[24] 王玮, 刘娜, 徐亚文, 等. 澜沧江中下游流域古茶树资源儿茶素含量的多样性分析[J/OL]. 分子植物育种, 2022: 1-17[2023-09-12]. http://kns.cnki.net/kcms/detail/46.1068.S.20220720.1902.009.html.
Wang W, Liu N, Xu Y W, et al. Diversity analysis of catechin content of ancient tea tree resources in the middle and lower reaches of Lancang River [J/OL]. Molecular Plant Breeding, 2022: 1-17[2023-09-12]. http://kns.cnki.net/ kcms/detail/46.1068.S.20220720.1902.009.html.
[25] 沈雪梅, 杨丕琼, 许文徽, 等. 十里香茶产业化发展的都市农庄模式[J]. 云南农业, 2014(11): 42-43.
Shen X M, Yang P Q, Xu W H, et al.Urban farm model of Industrialization development of Shilixiang tea[J]. Yunnan Agriculture, 2014(11): 42-43.
[26] 沈晓进. 昆明十里香古茶树保护与利用的探讨[J]. 西南林学院学报, 2004(2): 27-29.
Shen X J.Discussion on protection and utilization of Kunming Shilixiang ancient tea tree[J]. Journal of Southwest Forestry College, 2004(2): 27-29.
[27] 沈雪梅, 杨丕琼, 许文徽, 等. 云南十里香茶的保护现状及发展研究[C]//中国科学技术协会, 云南省人民政府. 第十六届中国科协年会——分12茶学青年科学家论坛论文集. 昆明: [出版者不详], 2014: 40-43.
Shen X M, Yang P Q, Xu W H, et al.Study on conservation status and development of Shilixiang tea in Yunnan [C]//China Association for Science and Technology, People's Government of Yunnan Province. The 16th Annual Meeting of China Association for Science and Technology: 12 Collection of Essays for the Forum of Young Tea Science Scientists. Kunming: [s.n.], 2014: 40-43.
[28] McInnes L, Healy J, Melville J. UMAP: uniform manifold approximation and projection for dimension reduction[J]. ArXiv, 2018: 1802.03426. doi: 10.48550/arXiv.1802.03426.
[29] Van der Maaten L. Accelerating t-SNE using tree-based algorithms[J]. Journal of Machine Learning Research, 2014(15): 3221-3245.
[30] Muthusamy M, Kim J Y, Yoon E K, et al.BrEXLB1, a Brassica rapa expansin-like B1 gene is associated with root development, drought stress response, and seed germination[J]. Genes, 2020, 11(4): 404. doi: 10.3390/genes11040404.
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