{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T05:06:35Z","timestamp":1784264795783,"version":"3.55.0"},"reference-count":37,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T00:00:00Z","timestamp":1784073600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Special Project of the State Key Laboratory of Woody Oil Resources Utilization, Ministry of Science and Technology","award":["2025ZYT027"],"award-info":[{"award-number":["2025ZYT027"]}]},{"DOI":"10.13039\/501100004735","name":"Natural Science Foundation of Hunan Province","doi-asserted-by":"crossref","award":["kq2208098"],"award-info":[{"award-number":["kq2208098"]}],"id":[{"id":"10.13039\/501100004735","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100004735","name":"Natural Science Foundation of Hunan Province","doi-asserted-by":"crossref","award":["kq2208099"],"award-info":[{"award-number":["kq2208099"]}],"id":[{"id":"10.13039\/501100004735","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Innovation Demonstration Project of Chenzhou City","award":["2022sfq53"],"award-info":[{"award-number":["2022sfq53"]}]},{"name":"Science and Technology Plan Major Project of Changsha City","award":["kq2301004"],"award-info":[{"award-number":["kq2301004"]}]},{"name":"Forestry technology research and innovation projects","award":["XLK202410"],"award-info":[{"award-number":["XLK202410"]}]},{"name":"Forestry technology research and innovation projects","award":["XLK202411"],"award-info":[{"award-number":["XLK202411"]}]},{"name":"National Key Research and Development Project","award":["2024YFB4205901"],"award-info":[{"award-number":["2024YFB4205901"]}]},{"name":"Central Forestry Promotion Demonstration Project","award":["[2023]XT06"],"award-info":[{"award-number":["[2023]XT06"]}]},{"name":"Central Forestry Promotion Demonstration Project","award":["[2023]XT28"],"award-info":[{"award-number":["[2023]XT28"]}]},{"name":"Yuelushan Laboratory Talent Program","award":["2025RC2087"],"award-info":[{"award-number":["2025RC2087"]}]},{"name":"Yuelushan Laboratory Talent Program","award":["2025RC2086"],"award-info":[{"award-number":["2025RC2086"]}]},{"name":"National Improved Variety Demonstration Base Projects for Cornus wilsoniana and Litsea cubeba"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Plants"],"abstract":"<jats:p>Sapindus mukorossi, known as soapberry, is a multipurpose woody species with oil-rich kernels and saponin-rich pulp, and its kernel oil and pulp saponins have important applications in oleochemicals, detergents, cosmetics, pharmaceuticals, and bioenergy. However, the mechanism by which carbohydrate-derived carbon is differentially allocated to kernel oil biosynthesis and pulp saponin biosynthesis within the same fruit remains unclear. In this study, we integrated morphological, physiological, metabolomic, and transcriptomic analyses to investigate the developmental accumulation patterns of oil and saponins and their relationship with carbohydrate metabolism in S. mukorossi fruit. The fruit reached maturity at approximately 130 days after flowering and was divided into four developmental stages: slow growth, rapid expansion, color transition, and maturation. Kernel oil accumulated in a typical S-shaped pattern and increased rapidly during the middle-to-late developmental stages, whereas pulp saponins increased continuously before maturity and remained stable. At maturity, soluble sugars mainly accumulated in the pulp, while starch was relatively enriched in the kernels, indicating different carbohydrate storage and utilization patterns between the two tissues. Integrated transcriptomic and metabolomic analyses revealed tissue-specific metabolic regulation: lipid metabolism was preferentially enriched in kernels, whereas terpenoid and secondary metabolic pathways were more active in pulp. Several genes related to fatty acid assembly and oil accumulation, including SmACC, SmLACS, SmGPAT, and SmLPAT, showed kernel-biased expression, while genes involved in the mevalonate (MVA)-dependent triterpenoid saponin pathway, including SmACCT, SmMVK, SmIDI, SmSQE, and SmLUP2, were closely associated with pulp saponin accumulation. Hormone-related transcription factors, such as GRAS and BES1 in kernels and MYC2 in pulp, may contribute to the coordination between carbohydrate metabolism and oil or saponin biosynthesis. Overall, these findings suggest that oil and saponin accumulation in S. mukorossi fruit are regulated by distinct tissue-specific metabolic programs closely linked to carbohydrate metabolism. This study provides new insights into carbon allocation between kernel oil and pulp saponin biosynthesis and identifies candidate pathways and genes for the genetic improvement and resource utilization of S. mukorossi.<\/jats:p>","DOI":"10.3390\/plants15142173","type":"journal-article","created":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T01:05:07Z","timestamp":1784163907000},"page":"2173","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Molecular Mechanisms of Oil and Saponin Accumulation and the Regulation of Carbohydrate Metabolism in Sapindus mukorossi Fruit"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3844-0725","authenticated-orcid":false,"given":"Xiao","family":"Zhou","sequence":"first","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changzhu","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunzhu","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1790-8720","authenticated-orcid":false,"given":"Yan","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiang","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenbin","family":"Zeng","sequence":"additional","affiliation":[{"name":"College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9618-0840","authenticated-orcid":false,"given":"Luhong","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"},{"name":"College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lijuan","family":"Jiang","sequence":"additional","affiliation":[{"name":"College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhihong","family":"Xiao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration on Utilization Science for Southern Woody Oilseed, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuena","family":"Ji","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peiwang","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingzhen","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Woody Oil Resources Utilization, Hunan Academy of Forestry, Changsha 410018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Sochacki, M., and Vogt, O. (2022). Triterpenoid saponins from washnut (Sapindus mukorossi Gaertn.)\u2014A source of natural surfactants and other active components. Plants, 11.","DOI":"10.3390\/plants11182355"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Zhou, X., Jiang, L.J., Li, P.W., Chen, J.Z., Chen, Y.Z., Yang, Y., Zhang, L.H., Ji, Y.N., Xiao, Z.H., and Sheng, K.Z. (2024). The Biosynthesis Pattern and Transcriptome Analysis of Sapindus saponaria Oil. Plants, 13.","DOI":"10.3390\/plants13131781"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.energy.2013.07.065","article-title":"Production and characterization of biodiesel obtained from Sapindus mukorossi kernel oil","volume":"60","author":"Chakraborty","year":"2013","journal-title":"Energy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"113552","DOI":"10.1016\/j.jep.2020.113552","article-title":"Saponin fraction from Sapindus mukorossi Gaertn as a novel cosmetic additive: Extraction, biological evaluation, analysis of anti-acne mechanism and toxicity prediction","volume":"268","author":"Wei","year":"2021","journal-title":"J. Ethnopharmacol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.jprot.2019.02.003","article-title":"Comparative analysis of proteomic and metabolomic profiles of different species of Paris","volume":"200","author":"Liu","year":"2019","journal-title":"J. Proteom."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e14552","DOI":"10.1111\/ppl.14552","article-title":"Regulation of exogenous sugars on the biosynthesis of key secondary metabolites in Cyclocarya paliurus","volume":"176","author":"Zhang","year":"2024","journal-title":"Physiol. Plant."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"uhae058","DOI":"10.1093\/hr\/uhae058","article-title":"RNA sequencing analysis reveals PgbHLH28 as the key regulator in response to methyl jasmonate-induced saponin accumulation in Platycodon grandiflorus","volume":"11","author":"Zhang","year":"2024","journal-title":"Hortic. Res."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Aluko, O.O., Li, C.Z., Wang, Q., and Liu, H.B. (2021). Sucrose Utilization for Improved Crop Yields: A Review Article. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22094704"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Lemoine, R., La Camera, S., Atanassova, R., D\u00e9dald\u00e9champ, F., Allario, T., Pourtau, N., Bonnemain, J.L., Laloi, M., Coutos-Th\u00e9venot, P., and Maurousset, L. (2013). Source-to-sink transport of sugar and regulation by environmental factors. Front. Plant Sci., 4.","DOI":"10.3389\/fpls.2013.00272"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Zeng, Z., Lyu, T., Jia, X., Chen, Y., and Lyu, Y.M. (2022). Expression Patterns of Sugar Transporter Genes in the Allocation of Assimilates and Abiotic Stress in Lily. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23084319"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1111\/j.1365-313X.2007.03268.x","article-title":"The soybean Dof-type transcription factor genes, GmDof4 and GmDof11, enhance lipid content in the seeds of transgenic Arabidopsis plants","volume":"52","author":"Wang","year":"2007","journal-title":"Plant J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7095","DOI":"10.1021\/acs.jafc.2c01672","article-title":"Metabolome and Transcriptome Analysis Reveals the Transcriptional Regulatory Mechanism of Triterpenoid Saponin Biosynthesis in Soapberry (Sapindus mukorossi Gaertn.)","volume":"70","author":"Xu","year":"2022","journal-title":"J. Agric. Food Chem."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wu, Q.K., Cao, Y.Y., Chen, C., Gao, Z.Z., Yu, F.Y., and Guy, R.D. (2020). Transcriptome analysis of metabolic pathways associated with oil accumulation in developing seed kernels of Styrax tonkinensis, a woody biodiesel species. BMC Plant Biol., 20.","DOI":"10.1186\/s12870-020-2327-4"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Li, W.J., Jiang, L.J., Chen, Y.Z., Li, C.Z., Li, P.W., Yang, Y., Chen, J.Z., and Liu, Q. (2023). Transcriptome Analysis Unveiled the Intricate Interplay between Sugar Metabolism and Lipid Biosynthesis in Symplocos paniculate Fruit. Plants, 12.","DOI":"10.3390\/plants12142703"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Zhang, L.H., Zhou, X., Chen, Y.Z., Li, P.W., Yang, Y., Li, C.Z., and Chen, J.Z. (2022). Fruit Morphology and Fatty Acid Composition of Swida wilsoniana Populations Collected from Different Regions in Southern China. Forests, 13.","DOI":"10.3390\/f13111811"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Liu, Y.L., Huang, Z.D., Ao, Y., Li, W., and Zhang, Z.X. (2013). Transcriptome analysis of yellow horn (Xanthoceras sorbifolia Bunge): A potential oil-rich seed tree for biodiesel in China. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0074441"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1590\/S0001-37652007000400002","article-title":"Antifungal activity of the extracts and saponins from Sapindus saponaria L.","volume":"79","author":"Tsuzuki","year":"2007","journal-title":"An. Acad. Bras. Cienc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11657","DOI":"10.1038\/s41598-021-91143-0","article-title":"Metabolomics analysis of the soapberry (Sapindus mukorossi Gaertn.) pericarp during fruit development and ripening based on UHPLC-HRMS","volume":"11","author":"Xu","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1093\/mp\/sss015","article-title":"Structure and dynamics of the isoprenoid pathway network","volume":"5","author":"Coman","year":"2012","journal-title":"Mol. Plant"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Zhou, M.Z., Fan, J.L., Gao, Y.H., Zheng, C.Y., Xu, Y.Y., Jia, L.M., An, X.M., and Chen, Z. (2024). Identification and analysis of UGT genes associated with triterpenoid saponin in soapberry (Sapindus mukorossi Gaertn.). BMC Plant Biol., 24.","DOI":"10.1186\/s12870-024-05281-4"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhang, Y.M., Chen, Q.C., Huang, Y.H., Zhao, R.Q., Sun, J., Yuan, X.D., Xu, H.M., Liu, H.Y., and Wu, Y.S. (2021). Gene excavation and expression analysis of CYP and UGT related to the post-modifying stage of gypenoside biosynthesis in Gynostemma pentaphyllum (Thunb.) Makino by comprehensive analysis of RNA and proteome sequencing. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0260027"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Li, Y.C., Zhao, J., Chen, H., Mao, Y.P., Yang, Y.P., Feng, L., Mo, C.X., Huang, L., Hou, D.B., and Yu, M. (2022). Transcriptome level reveals the triterpenoid saponin biosynthesis pathway of Bupleurum falcatum L.. Genes, 13.","DOI":"10.3390\/genes13122237"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1146\/annurev-arplant-050213-040251","article-title":"Sucrose metabolism: Gateway to diverse carbon use and sugar signaling","volume":"65","author":"Ruan","year":"2014","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1093\/mp\/ssp115","article-title":"The Arabidopsis bZIP1 transcription factor is involved in sugar signaling, protein networking, and DNA binding","volume":"3","author":"Kang","year":"2010","journal-title":"Mol. Plant"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3871","DOI":"10.1105\/tpc.113.114066","article-title":"ABI1 and PP2CA phosphatases are negative regulators of Snf1-related protein kinase1 signaling in Arabidopsis","volume":"25","author":"Rodrigues","year":"2013","journal-title":"Plant Cell"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1146\/annurev.arplant.51.1.49","article-title":"Sugar-induced signal transduction in plant","volume":"51","author":"Smeekens","year":"2000","journal-title":"Annu. Rev. Plant Physiol. Plant Mol. Biol."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Tsai, A.Y., and Gazzarrini, S. (2014). Trehalose-6-phosphate and SnRK1 kinases in plant development and signaling: The emerging picture. Front. Plant Sci., 5.","DOI":"10.3389\/fpls.2014.00119"},{"key":"ref_28","unstructured":"(2016). State Food and Drug Administration; National Food Safety Standard\u2014In Determination of Fats in Foods (Standard No. GB 5009.6-2016)."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"952","DOI":"10.1039\/D0NJ04047A","article-title":"Extraction and purification of saponins from Sapindus mukorossi","volume":"45","author":"Chen","year":"2021","journal-title":"New J. Chem."},{"key":"ref_30","unstructured":"(2023). General Administration of Quality Supervision; Inspection and Quarantine of the of China; Standardization Administration of China. National Food Safety Standard\u2014Determination of Fructose, Glucose, Sucrose, Maltose, Lactose in Foods (Standard No. GB 5009.8-2023)."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e4332","DOI":"10.21769\/BioProtoc.4332","article-title":"Measuring Endogenous GA and IAA","volume":"12","author":"Chen","year":"2022","journal-title":"Bio-Protocol"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Qi, B.B., Wu, C., Liang, H.L., Cui, K.H., Fahad, S., Wang, M.L., Liu, B.Y., Nie, L.X., Huang, J.L., and Tang, H. (2021). Optimized High-Performance Liquid Chromatography Method for Determining Nine Cytokinins, Indole-3-acetic Acid and Abscisic Acid. Sustainability, 13.","DOI":"10.3390\/su13136998"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"13737","DOI":"10.1021\/acs.analchem.9b03107","article-title":"Database-Assisted Globally Optimized Targeted Mass Spectrometry (dGOT-MS): Broad and Reliable Metabolomics Analysis with Enhanced Identification","volume":"91","author":"Shi","year":"2019","journal-title":"Anal. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"778","DOI":"10.1038\/nprot.2007.95","article-title":"Untargeted large-scale plant metabolomics using liquid chromatography coupled to mass spectrometry","volume":"2","author":"Moco","year":"2007","journal-title":"Nat. Protoc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"i884","DOI":"10.1093\/bioinformatics\/bty560","article-title":"fastp: An ultra-fast all-in-one FASTQ preprocessor","volume":"34","author":"Chen","year":"2018","journal-title":"Bioinformatics"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Li, B., and Dewey, C.N. (2011). RSEM: Accurate transcript quantification from RNA-Seq data with or without a reference genome. BMC Bioinform., 12.","DOI":"10.1186\/1471-2105-12-323"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1186\/s13059-014-0550-8","article-title":"Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2","volume":"15","author":"Love","year":"2014","journal-title":"Genome Biol."}],"container-title":["Plants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/14\/2173\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T04:36:22Z","timestamp":1784262982000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/14\/2173"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,15]]},"references-count":37,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["plants15142173"],"URL":"https:\/\/doi.org\/10.3390\/plants15142173","relation":{},"ISSN":["2223-7747"],"issn-type":[{"value":"2223-7747","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,15]]}}}