{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T05:06:53Z","timestamp":1789016813341,"version":"build-2803163510"},"reference-count":43,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Natural Science Foundation of Jiangxi Province","award":["20232BAB205038"],"award-info":[{"award-number":["20232BAB205038"]}]},{"name":"the Open Project of the State Key Laboratory of Woody Oil Resource Utilization Jointly Established by the Provincial and Ministry of China","award":["GZKF202104"],"award-info":[{"award-number":["GZKF202104"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Sugar composition is a critical determinant of fruit quality in fleshy fruits, influencing both organoleptic properties and nutritional value. Akebia trifoliata, an emerging fruit crop, possesses pulp rich in soluble sugars, vitamins, and polyphenols, making it suitable for fresh consumption, medicinal applications, and food processing. However, the molecular mechanisms governing sugar metabolism and accumulation in this species remain largely unexplored. We systematically evaluated the sugar content dynamics across different A. trifoliata germplasms and performed comparative transcriptomic analysis between high-sugar-accumulation (S4) and low-sugar-accumulation germplasms (S19) at three developmental stages (IM: the fruit is hard and immature; MA: the pulp remains firm, but the peel begins to soften and crack; and PM: the fruit is fully mature, and the pulp becomes shiny, translucent, soft, and edible). A total of 10,269 differentially expressed genes were identified with KEGG enrichment analysis, revealing significant enrichment in pathways directly associated with sugar biosynthesis. Through the analysis of weighted gene co-expression networks, a co-expression module significantly correlated with total sugar accumulation was identified, and qRT-PCR was used to verify that the expression levels of 29 candidate genes involved in carbohydrate synthesis were higher in the high-sugar-accumulation type than in the low-sugar-accumulation germplasm. These findings not only advance our understanding of the molecular basis of fruit quality development in this underutilized crop but also lay the foundation for the future breeding of A. trifoliata varieties with high-sugar greater nutritional value and processing qualities for the food industry.<\/jats:p>","DOI":"10.3390\/life16091459","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T01:05:26Z","timestamp":1788224726000},"page":"1459","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Transcriptomic Analysis Reveals Sugar Metabolism and Accumulation Mechanisms in Akebia trifoliata Fruits"],"prefix":"10.3390","volume":"16","author":[{"given":"Juan","family":"Niu","sequence":"first","affiliation":[{"name":"School of Biological and Environmental Engineering, Jingdezhen University, Jingdezhen 333032, China"},{"name":"National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haili","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Tropical Agriculture and Forestry, Hainan University, Danzhou 571737, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhimin","family":"Sun","sequence":"additional","affiliation":[{"name":"Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuanhe","family":"Wei","sequence":"additional","affiliation":[{"name":"School of Biological and Environmental Engineering, Jingdezhen University, Jingdezhen 333032, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guifa","family":"Cheng","sequence":"additional","affiliation":[{"name":"Fuliang County Agricultural and Rural Bureau, Jingdezhen 333403, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingbao","family":"Luan","sequence":"additional","affiliation":[{"name":"National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572000, China"},{"name":"Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/aob\/mcy057","article-title":"Putting primary metabolism into perspective to obtain better fruits","volume":"122","author":"Beauvoit","year":"2018","journal-title":"Ann. Bot."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Wu, J., Lu, L., Meng, Z., Qin, Y., Guo, L., Ran, M., Peng, P., Tang, Y., Huang, G., and Li, W. (2025). Advancements on the mechanism of soluble sugar metabolism in fruits. Horticulturae, 11.","DOI":"10.3390\/horticulturae11091001"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Gou, N., Chen, C., Huang, M., Zhang, Y., Bai, H., Li, H., Wang, L., and Wuyun, T. (2023). Transcriptome and metabolome analyses reveal sugar and acid accumulation during apricot fruit development. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms242316992"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Su, L., Zhang, T., Wu, M., Zhong, Y., and Cheng, Z. (2023). Transcriptome and metabolome reveal sugar and organic acid accumulation in Rosa roxburghii fruit. Plants, 12.","DOI":"10.3390\/plants12173036"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"107955","DOI":"10.1016\/j.plaphy.2023.107955","article-title":"Sugar composition and transcriptome analysis in developing \u2018Fengtang\u2019plum (Prunus salicina Lindl.) reveal candidate genes regulating sugar accumulation","volume":"202","author":"Nie","year":"2023","journal-title":"Plant Physiol. Biochem."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Gao, L., Zhao, S., Lu, X., He, N., Zhu, H., Dou, J., and Liu, W. (2018). Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0190096"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1186\/s43897-024-00100-8","article-title":"From acidity to sweetness: A comprehensive review of carbon accumulation in grape berries","volume":"4","author":"Lu","year":"2024","journal-title":"Mol. Hortic."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1038\/s41438-021-00628-6","article-title":"Transcripts switched off at the stop of phloem unloading highlight the energy efficiency of sugar import in the ripening V. vinifera fruit","volume":"8","author":"Savoi","year":"2021","journal-title":"Hortic. Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"He, Y., Chen, R., Yang, Y., Liang, G., Zhang, H., Deng, X., and Xi, R. (2022). Sugar metabolism and transcriptome analysis reveal key sugar transporters during Camellia oleifera fruit development. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23020822"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"24964","DOI":"10.1038\/s41598-024-74929-w","article-title":"Sustained carbon import supports sugar accumulation and anthocyanin biosynthesis during fruit development and ripening in blueberry (Vaccinium ashei)","volume":"14","author":"Acharya","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Yang, J., Zhang, J., Niu, X.Q., Zheng, X.L., Chen, X., Zheng, G.H., and Wu, J.C. (2021). Comparative transcriptome analysis reveals key genes potentially related to organic acid and sugar accumulation in loquat. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0238873"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Huang, P., Zang, F., Li, C., Lin, F., Zang, D., Li, B., and Zheng, Y. (2022). The Akebia genus as a novel forest crop: A review of its genetic resources, nutritional components, biosynthesis, and biological studies. Front. Plant Sci., 13.","DOI":"10.3389\/fpls.2022.936571"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Jiang, Y., Du, Y., Chen, C., Wang, D., Zhong, Y., and Deng, Y. (2023). Integrative metabolomic and transcriptomic landscape during Akebia trifoliata fruit ripening and cracking. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms242316732"},{"key":"ref_14","first-page":"823","article-title":"Developmental stages of Akebia trifoliata fruit based on volume","volume":"39","author":"Yang","year":"2021","journal-title":"Hortic. Sci. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e142","DOI":"10.1002\/efd2.142","article-title":"Akebia fruit: A review on its extraction, phytochemicals, bioactivities and applications","volume":"5","author":"Li","year":"2024","journal-title":"eFood"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1001\/jama.2020.18936","article-title":"Management of Crohn Disease: A Review","volume":"325","author":"Cushing","year":"2021","journal-title":"JAMA"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Wang, M., Guo, X., and Song, J. (2022). Analysis of the shape characteristics and nutritional components of Akebia trifoliata in Qinba Mountains. Front. Plant Sci., 13.","DOI":"10.3389\/fpls.2022.975677"},{"key":"ref_18","first-page":"100312","article-title":"Integrated transcriptomic and metabolomic analyses delineate the biosynthetic pathways of functional components in maturing Akebia trifoliata fruit","volume":"11","author":"Nazir","year":"2025","journal-title":"Food Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"888","DOI":"10.1093\/plphys\/kiad294","article-title":"An update on sugar allocation and accumulation in fruits","volume":"193","author":"Ren","year":"2023","journal-title":"Plant Physiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"712","DOI":"10.1016\/j.pld.2022.12.001","article-title":"Germplasm resources and genetic improvement of Akebia: A new fruit crop in China","volume":"45","author":"Zou","year":"2023","journal-title":"Plant Divers."},{"key":"ref_21","first-page":"75","article-title":"QTL analysis for total sugar content in watermelon","volume":"30","author":"Liu","year":"2013","journal-title":"J. Fruit Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1021\/jf60133a007","article-title":"Plant Tissue Analysis, Colorimetric Determination of Glucose, Fructose, and Sucrose in Plant Materials Using a Combination of Enzymatic and Chemical Methods","volume":"12","author":"Johnson","year":"1964","journal-title":"Agric. Food Chem."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Jain, A., Jain, R., and Jain, S. (2020). Quantitative analysis of reducing sugars by 3, 5-dinitrosalicylic acid (DNSA method). Basic Techniques in Biochemistry, Microbiology and Molecular Biology: Principles and Techniques, Springer.","DOI":"10.1007\/978-1-4939-9861-6_43"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Huang, Y., Wang, Y., Sun, Z., Wang, G., Niu, J., and Luan, M. (2025). Co-expression network analysis identifies AtrANS, a gene essential for anthocyanin pigmentation in Akebia trifoliata pericarp. BMC Plant Biol., 25.","DOI":"10.1186\/s12870-025-07162-w"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2114","DOI":"10.1093\/bioinformatics\/btu170","article-title":"Trimmomatic: A flexible trimmer for Illumina sequence data","volume":"15","author":"Bolger","year":"2014","journal-title":"Bioinformatics"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"133313","DOI":"10.1016\/j.ijbiomac.2024.133313","article-title":"The \u03b2-galactosidase gene AtrBGAL2 regulates Akebia trifoliata fruit cracking","volume":"275","author":"Niu","year":"2024","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_27","unstructured":"Anders, S., and Huber, W. (2013). Differential Expression of RNA-Seq Data at the Gene Level\u2014The DESeq Package, European Molecular Biology Laboratory (EMBL)."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Langfelder, P., and Horvath, S. (2008). WGCNA: An R package for weighted correlation network analysis. BMC Bioinform., 9.","DOI":"10.1186\/1471-2105-9-559"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Mason, M.J., Fan, G., Plath, K., Zhou, Q., and Horvath, S. (2009). Signed weighted gene co-expression network analysis of transcriptional regulation in murine embryonic stem cells. BMC Genom., 10.","DOI":"10.1186\/1471-2164-10-327"},{"key":"ref_30","first-page":"189","article-title":"A study on the biological characteristics and nutritional composition of the fruits of Akebia trifoliate","volume":"11","author":"Li","year":"1991","journal-title":"Guihaia"},{"key":"ref_31","first-page":"5","article-title":"Nutritional analysis of the fruits of Akebia Trifoliate","volume":"18","author":"Yi","year":"2023","journal-title":"Contemp. Hortic."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Ke, D., Zhang, Y., Teng, Y., and Zhao, X. (2025). Transcriptomic profiling uncovers molecular basis for sugar and acid metabolism in two pomegranate (Punica granatum) Varieties. Foods, 14.","DOI":"10.3390\/foods14101755"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"uhae133","DOI":"10.1093\/hr\/uhae133","article-title":"Sugar import mediated by sugar transporters and cell wall invertases for seed development in Camellia oleifera","volume":"11","author":"Du","year":"2024","journal-title":"Hortic. Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.pbi.2004.03.014","article-title":"Sucrose metabolism: Regulatory mechanisms and pivotal roles in sugar sensing and plant development","volume":"7","author":"Koch","year":"2004","journal-title":"Curr. Opin. Plant Biol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Zhang, F., Li, Z., Zhou, J., Gu, Y., and Tan, X. (2021). Comparative study on fruit development and oil synthesis in two cultivars of Camellia oleifera. BMC Plant Biol., 21.","DOI":"10.1186\/s12870-021-03114-2"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"253","DOI":"10.3724\/SP.J.1006.2014.00253","article-title":"Cloning and expression analysis of sugarcane alkaline\/neutral invertase gene SoNIN1","volume":"40","author":"Niu","year":"2014","journal-title":"Acta Agron. Sin."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Liu, S., Nie, X., Chen, H., and Shen, X. (2025). Correction: Identification of the SWEET gene family and functional characterization of PsSWEET1a and PsSWEET17b in the regulation of sugar accumulation in \u2018Fengtang\u2019 plum (Prunus salicina Lindl.). BMC Plant Biol., 25.","DOI":"10.1186\/s12870-025-06561-3"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Liao, G., Li, Y., Wang, H., Liu, Q., Zhong, M., Jia, D., Huang, C., and Xu, X. (2022). Genome-wide identification and expression profiling analysis of sucrose synthase (SUS) and sucrose phosphate synthase (SPS) genes family in Actinidia chinensis and A. eriantha. BMC Plant Biol., 22.","DOI":"10.1186\/s12870-022-03603-y"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1038\/s41438-018-0064-8","article-title":"Sugar metabolism and accumulation in the fruit of transgenic apple trees with decreased sorbitol synthesis","volume":"5","author":"Li","year":"2018","journal-title":"Hortic. Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1111\/pbi.12756","article-title":"A comprehensive investigation of starch degradation process and identification of a transcriptional activator MabHLH6 during banana fruit ripening","volume":"16","author":"Xiao","year":"2018","journal-title":"Plant Biotechnol. J."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"3723","DOI":"10.1016\/j.jia.2024.09.001","article-title":"Genome-wide identification, molecular evolution, and functional characterization of fructokinase gene family in Apple reveal its role in improving salinity tolerance","volume":"23","author":"Su","year":"2024","journal-title":"J. Integr. Agric."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Stein, O., and Granot, D. (2018). Plant fructokinases: Evolutionary, developmental, and metabolic aspects in sink tissues. Front. Plant Sci., 9.","DOI":"10.3389\/fpls.2018.00339"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1186\/s43897-025-00156-0","article-title":"A subgroup I bZIP transcription factor PpbZIP18 plays an important role in sucrose accumulation in peach","volume":"5","author":"Zhang","year":"2025","journal-title":"Mol. Hortic."}],"container-title":["Life"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-1729\/16\/9\/1459\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T04:10:57Z","timestamp":1789013457000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-1729\/16\/9\/1459"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,31]]},"references-count":43,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["life16091459"],"URL":"https:\/\/doi.org\/10.3390\/life16091459","relation":{},"ISSN":["2075-1729"],"issn-type":[{"value":"2075-1729","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,31]]}}}