{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T15:03:39Z","timestamp":1790003019008,"version":"4.0.1"},"reference-count":46,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007129","name":"Shandong Provincial Natural Science Foundation","doi-asserted-by":"publisher","award":["ZR2026MS0628"],"award-info":[{"award-number":["ZR2026MS0628"]}],"id":[{"id":"10.13039\/501100007129","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100015335","name":"Modern Agricultural Technology Industry System of Shandong Province","doi-asserted-by":"publisher","award":["SDAIT-26"],"award-info":[{"award-number":["SDAIT-26"]}],"id":[{"id":"10.13039\/501100015335","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Key R&D Program of Shandong Province","award":["2025TSGCCZZB0237"],"award-info":[{"award-number":["2025TSGCCZZB0237"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Mar. Drugs","Marine Drugs"],"abstract":"<jats:p>Brown algae contain phlorotannins with recognized biological and ecological functions, but the responses of phenolic metabolism to different light environments remain incompletely understood. In this study, Sargassum muticum was cultivated for 15 days under different photoperiods (12L:12D, 16L:8D, and 20L:4D) and light qualities (white, blue, and red light). Growth, photosynthetic performance, oxidative stress indicators, and phlorotannin content were examined, together with transcriptomic and untargeted metabolomic responses. Extended photoperiods were associated with increased growth and a transient increase in phlorotannin content, whereas blue light reduced growth but maintained relatively high chlorophyll a content and photosynthetic efficiency. Transcriptomic analysis identified 10,322, 3790, and 9301 differentially expressed genes under long-photoperiod, blue-light, and red-light treatments, respectively, including 388 genes shared among the three comparisons. Seven transcripts were putatively annotated as polyketide synthases, including four candidate type III polyketide synthase transcripts, and 26 transcripts were annotated as candidate acetyl-CoA carboxylase-related sequences. Untargeted LC\u2013MS analysis yielded 949 putatively annotated metabolites, among which features annotated as salicylic acid and \u03b3-glutamylcysteine showed increased relative abundance under the three light treatments. A feature putatively annotated as phloroglucinol did not differ significantly among treatments. Correlation analysis indicated coordinated, but non-causal, associations between light-responsive transcripts and changes in amino acid, carbohydrate, and lipid metabolism. These results characterize the physiological and multi-omics responses of S. muticum to altered light regimes and provide candidate molecular targets for future functional and targeted chemical validation.<\/jats:p>","DOI":"10.3390\/md24090330","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:12:09Z","timestamp":1789999929000},"page":"330","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of Photoperiod and Light Quality on Phlorotannin Accumulation and Multi-Omics Responses in Sargassum muticum"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1430-1432","authenticated-orcid":false,"given":"Fang","family":"L\u00fc","sequence":"first","affiliation":[{"name":"Shandong Engineering Research Center of Nearshore Seaweed Bed Building, Marine Science Research Institute of Shandong Province (National Oceanographic Center, Qingdao), Qingdao 266104, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Yan","family":"Li","sequence":"additional","affiliation":[{"name":"Shandong Engineering Research Center of Nearshore Seaweed Bed Building, Marine Science Research Institute of Shandong Province (National Oceanographic Center, Qingdao), Qingdao 266104, China"},{"name":"School of Fisheries, Ludong University, Yantai 264025, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"given":"Dongmei","family":"Zhan","sequence":"additional","affiliation":[{"name":"Shandong Engineering Research Center of Nearshore Seaweed Bed Building, Marine Science Research Institute of Shandong Province (National Oceanographic Center, Qingdao), Qingdao 266104, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Haiyi","family":"Wu","sequence":"additional","affiliation":[{"name":"Shandong Engineering Research Center of Nearshore Seaweed Bed Building, Marine Science Research Institute of Shandong Province (National Oceanographic Center, Qingdao), Qingdao 266104, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e2209637120","DOI":"10.1073\/pnas.2209637120","article-title":"Oceanographic connectivity explains the intra-specific diversity of mangrove forests at global scales","volume":"120","author":"Fragkopoulou","year":"2023","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"152049","DOI":"10.1016\/j.jembe.2024.152049","article-title":"Coupling effects of CO2-induced ocean acidification and nitrogen enrichment on growth, photosynthesis and nitrogen utilization of an invasive seaweed (Sargassum muticum)","volume":"579","author":"Yan","year":"2024","journal-title":"J. Exp. Mar. Biol. Ecol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1324","DOI":"10.1111\/raq.12524","article-title":"Kelp aquaculture in China: A retrospective and future prospects","volume":"13","author":"Hu","year":"2021","journal-title":"Rev. Aquac."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2521","DOI":"10.1007\/s10811-017-1086-6","article-title":"Total phenolic content and biological activities of enzymatic extracts from Sargassum muticum (Yendo) Fensholt","volume":"29","author":"Puspita","year":"2017","journal-title":"J. Appl. Phycol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Catarino, M.D., Silva-Reis, R., Chouh, A., Silva, S., Braga, S.S., Silva, A.M.S., and Cardoso, S.M. (2023). Applications of antioxidant secondary metabolites of Sargassum spp. Mar. Drugs, 21.","DOI":"10.3390\/md21030172"},{"key":"ref_6","first-page":"11483","article-title":"Advances in the biorefinery of Sargassum muticum: Valorisation of the alginate fractions","volume":"138","author":"Torres","year":"2019","journal-title":"Ind. Crops Prod."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"100832","DOI":"10.1016\/j.fbio.2020.100832","article-title":"Phlorotannins: A review on biosynthesis, chemistry and bioactivity","volume":"39","author":"Shrestha","year":"2020","journal-title":"Food Biosci."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Zheng, H., Zhao, Y., and Guo, L. (2022). A bioactive substance derived from brown seaweeds: Phlorotannins. Mar. Drugs, 20.","DOI":"10.3390\/md20120742"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Cotas, J., Leandro, A., Monteiro, P., Pacheco, D., Figueirinha, A., Gon\u00e7alves, A.M.M., da Silva, G.J., and Pereira, L. (2020). Seaweed phenolics: From extraction to applications. Mar. Drugs, 18.","DOI":"10.3390\/md18080384"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Sim\u00f3n, L., Arazo-Rusindo, M., Quest, A.F.G., and Mariotti-Celis, M.S. (2023). Phlorotannins: Novel orally administrated bioactive compounds that induce mitochondrial dysfunction and oxidative stress in cancer. Antioxidants, 12.","DOI":"10.3390\/antiox12091734"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Herath, K.H.I.N.M., Nagahawatta, D.P., Wang, L., and Sanjeewa, K.K.A. (2025). The Role of phlorotannins to treat inflammatory diseases. Chemistry, 7.","DOI":"10.3390\/chemistry7030077"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1007\/s10811-007-9254-8","article-title":"Antioxidant activities of phlorotannins isolated from Japanese Laminariaceae","volume":"20","author":"Shibata","year":"2008","journal-title":"J. Appl. Phycol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1007\/s10811-023-02913-4","article-title":"Phlorotannins from brown algae: A review on their antioxidant mechanisms and applications in oxidative stress-mediated diseases","volume":"35","author":"Phang","year":"2023","journal-title":"J. Appl. Phycol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Birkemeyer, C., Lemesheva, V., Billig, S., and Tarakhovskaya, E. (2020). Composition of intracellular and cell wall-bound phlorotannin fractions in fucoid algae indicates specific functions of these metabolites dependent on the chemical structure. Metabolites, 10.","DOI":"10.3390\/metabo10090369"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/S0304-3770(02)00035-9","article-title":"Induction, exudation and the UV protective role of kelp phlorotannins","volume":"73","author":"Swanson","year":"2002","journal-title":"Aquat. Bot."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1007\/s10886-005-0984-2","article-title":"Contents of soluble, cell-wall-bound and exuded phlorotannins in the brown alga Fucus vesiculosus, with implications on their ecological functions","volume":"31","author":"Koivikko","year":"2005","journal-title":"J. Chem. Ecol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"70","DOI":"10.21638\/spbu03.2018.108","article-title":"Physiological functions of phlorotannins","volume":"63","author":"Lemesheva","year":"2018","journal-title":"Biol. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3089","DOI":"10.1105\/tpc.113.111336","article-title":"Structure\/function analysis of a type III polyketide synthase in the brown alga Ectocarpus siliculosus reveals a biochemical pathway in phlorotannin monomer biosynthesis","volume":"25","author":"Delage","year":"2013","journal-title":"Plant Cell"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"14643","DOI":"10.1021\/acs.jafc.1c05868","article-title":"A Type III Polyketide synthase (SfuPKS1) isolated from the edible seaweed Sargassum fusiforme exhibits broad substrate and catalysis specificity","volume":"69","author":"Zhao","year":"2021","journal-title":"J. Agric. Food Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1080\/09670262.2019.1709131","article-title":"Vanadium-dependent haloperoxidase activity and phlorotannin incorporation into the cell wall during early embryogenesis of Fucus vesiculosus (Phaeophyceae)","volume":"55","author":"Lemesheva","year":"2020","journal-title":"Eur. J. Phycol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1515\/BOT.2004.057","article-title":"Interspecific and temporal variation in phlorotannin levels in an assemblage of brown algae","volume":"47","author":"Connan","year":"2004","journal-title":"Bot. Mar."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1080\/09670260802578542","article-title":"Seasonal variation of polyphenolics in Ascophyllum nodosum (Phaeophyceae)","volume":"44","author":"Parys","year":"2009","journal-title":"Eur. J. Phycol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1111\/j.1440-1835.2009.00558.x","article-title":"Seasonal variation of phlorotannin in sargassacean species from the coast of the sea of Japan","volume":"58","author":"Kamiya","year":"2010","journal-title":"Phycol. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1709","DOI":"10.1007\/s10811-022-02736-9","article-title":"Characterization of a type III polyketide synthase (sjPKS1) gene and its expression in response to light in the economic brown alga Saccharina japonica","volume":"34","author":"Li","year":"2022","journal-title":"J. Appl. Phycol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1111\/j.1529-8817.2004.03103.x","article-title":"Effects of UV radiation on growth and phlorotannins in Fucus gardneri (Phaeophyceae) juveniles and embryos","volume":"40","author":"Henry","year":"2004","journal-title":"J. Phycol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1080\/09670262.2025.2512326","article-title":"The influence of light on phlorotannin content of brown macroalgae","volume":"60","author":"McKinney","year":"2025","journal-title":"Eur. J. Phycol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1111\/nph.16602","article-title":"Transcriptional regulatory network of the light signaling pathways","volume":"227","author":"Jing","year":"2020","journal-title":"New Phytol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Petersen, J., Rredhi, A., Szyttenholm, J., Oldemeyer, S., Kottke, T., and Mittag, M. (2021). The world of algae reveals a broad variety of cryptochrome properties and functions. Front. Plant Sci., 12.","DOI":"10.3389\/fpls.2021.766509"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Hallmann, A. (2025). Sensing a rainbow of colors: Algal photoreceptors. Front. Plant Sci., 16.","DOI":"10.3389\/fpls.2025.1684559"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3871","DOI":"10.1073\/pnas.1401871111","article-title":"Eukaryotic algal phytochromes span the visible spectrum","volume":"111","author":"Rockwell","year":"2014","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Maltsev, Y., Maltseva, K., Kulikovskiy, M., and Maltseva, S. (2021). Influence of light conditions on microalgae growth and content of lipids, carotenoids, and fatty acid composition. Biology, 10.","DOI":"10.3390\/biology10101060"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Lee, H., Depuydt, S., Shin, K., De Saeger, J., Han, T., and Park, J. (2024). Interactive effects of blue light and water turbulence on the growth of the green macroalga Ulva australis (Chlorophyta). Plants, 13.","DOI":"10.3390\/plants13020266"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/S0176-1617(00)80140-6","article-title":"Light quality effect on photosynthesis and efficiency of carbon assimilation in the red alga Porphyra leucosticta","volume":"157","author":"Aguilera","year":"2000","journal-title":"J. Plant Physiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"103820","DOI":"10.1016\/j.algal.2024.103820","article-title":"Unravelling the impact of light spectra on microalgal growth and biochemical composition using principal component analysis and artificial neural network models","volume":"85","author":"Esteves","year":"2025","journal-title":"Algal Res."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Endo, H., Moriyama, H., and Okumura, Y. (2023). Photoinhibition and photoprotective responses of a brown marine macroalga acclimated to different light and nutrient regimes. Antioxidants, 12.","DOI":"10.3390\/antiox12020357"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Carpena, M., Pereira, C., Silva, A., Barciela, P., Jorge, A.O.S., Perez-Vazquez, A., Pereira, A.G., Barreira, J.C.M., Oliveira, M., and Prieto, M.A. (2024). Metabolite profiling of macroalgae: Biosynthesis and beneficial biological properties of active compounds. Mar. Drugs, 22.","DOI":"10.3390\/md22100478"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1007\/s10142-016-0521-0","article-title":"RNA-seq analysis of the transcriptional response to blue and red light in the extremophilic red alga, Cyanidioschyzon merolae","volume":"16","author":"Tardu","year":"2016","journal-title":"Funct. Integr. Genom."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"19625","DOI":"10.1073\/pnas.0707692104","article-title":"AUREOCHROME, a photoreceptor required for photomorphogenesis in stramenopiles","volume":"104","author":"Takahashi","year":"2007","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1111\/j.1541-4337.2009.00093.x","article-title":"Phthalate esters in foods: Sources, occurrence, and analytical methods","volume":"9","author":"Cao","year":"2010","journal-title":"Compr. Rev. Food Sci. Food Saf."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1093\/plphys\/kiac449","article-title":"Jasmonic acid and salicylic acid modulate systemic reactive oxygen species signaling during stress responses","volume":"191","author":"Myers","year":"2023","journal-title":"Plant Physiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"891","DOI":"10.1093\/bib\/bbv090","article-title":"Transcriptomic and metabolomic data integration","volume":"17","author":"Cavill","year":"2016","journal-title":"Brief. Bioinform."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/S0015-3796(17)30778-3","article-title":"New spectrophotometric equations for determining chlorophylls a, b, c1, and c2 in higher plants, algae and natural phytoplankton","volume":"167","author":"Jeffrey","year":"1975","journal-title":"Biochem. Physiol. Pflanz."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0176-1617(11)81192-2","article-title":"The spectral determination of chlorophylls a and b, as well as total carotenoids, using various solvents with spectrophotometers of different resolution","volume":"144","author":"Wellburn","year":"1994","journal-title":"J. Plant Physiol."},{"key":"ref_44","first-page":"3","article-title":"Determination of vicinal phenolic hydroxylin brown algal polyphenol","volume":"24","author":"Yan","year":"2000","journal-title":"Mar. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"875","DOI":"10.1038\/nprot.2007.102","article-title":"Estimation of total phenolic content and other oxidation substrates in plant tissues using Folin\u2013Ciocalteu reagent","volume":"2","author":"Ainsworth","year":"2007","journal-title":"Nat. Protoc."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/s11306-007-0082-2","article-title":"Proposed minimum reporting standards for chemical analysis","volume":"3","author":"Sumner","year":"2007","journal-title":"Metabolomics"}],"container-title":["Marine Drugs"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-3397\/24\/9\/330\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:24:38Z","timestamp":1790000678000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-3397\/24\/9\/330"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,21]]},"references-count":46,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["md24090330"],"URL":"https:\/\/doi.org\/10.3390\/md24090330","relation":{},"ISSN":["1660-3397"],"issn-type":[{"value":"1660-3397","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,21]]}}}