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Plant Sci."],"abstract":"<jats:p>\n                    In controlled environments, light intensity and quality can be manipulated to enhance beneficial phytochemicals, vitamins, and foliage color by increasing anthocyanin levels before harvest. Our objectives were to quantify whether a 50% reduction in end-of-production (EOP) light intensity, enriched with blue (B) light alone or with red (R) light, would yield red leaf lettuce of comparable or higher quality than that grown under high-intensity white light. Seedlings of red leaf lettuce (\n                    <jats:italic>Lactuca sativa<\/jats:italic>\n                    ) \u2018Barlach\u2019, \u2018Rouxai\u2019, and \u2018Thurinus\u2019 were grown under light-emitting diodes (LEDs) that provided a photosynthetic photon flux density (PPFD) of 300 \u00b5mol\u00b7m\n                    <jats:sup>\u22122<\/jats:sup>\n                    \u00b7s\n                    <jats:sup>\u22121<\/jats:sup>\n                    with a ratio (%) of 19:39:39:3 B:green:R:far-red light. During the last 6\u20138 days of production, plants were either left in the same conditions or placed under LEDs providing a ratio (%) of 100:00, 75:25, or 50:50 B:R light and a PPFD of 150 \u00b5mol\u00b7m\n                    <jats:sup>\u22122<\/jats:sup>\n                    \u00b7s\n                    <jats:sup>\u22121<\/jats:sup>\n                    . Compared to untreated plants, the shoot fresh mass of \u2018Rouxai\u2019 was 16%, 17%, and 21% lower, and the shoot dry mass was 25%, 27%, and 29% lower under 100:00, 75:25, and 50:50 B:R EOP treatments, respectively. \u2018Thurinus\u2019 exposed to 100:00 B:R EOP lighting contained 22%, 22%, 47%, 35%, 24%, 10%, 40%, 31%, 25%, 50%, and 38% greater N, P, Ca, Mg, S, B, Cu, Fe, Mn, Mo, and Zn concentrations, respectively, compared to the control. Plants exposed to EOP generally developed increased concentrations of water-soluble vitamins. Vitamin C of \u2018Barlach\u2019, \u2018Rouxai\u2019, and \u2018Thurinus\u2019 was between 37% and 42%, 36% and 45%, and 49% and 57% greater, respectively, when exposed to EOP B or B:R sole-source lighting. The carotenoid concentration of \u2018Rouxai\u2019 under 100:00 B:R was 29% greater than that of the control. Each cultivar developed the highest concentration of violaxanthin, neoxanthin, zeaxanthin, and \u03b1-carotene when not exposed to EOP lighting. Under EOP lighting, \u2018Barlach\u2019, \u2018Rouxai\u2019, and \u2018Thurinus\u2019 accumulated between 52% and 68%, 55% and 57%, and 33% and 43% lower anthocyanin concentrations, respectively, than the control plants. Our results indicate that maintaining a higher light intensity during the EOP phase was more effective at increasing anthocyanin production in red leaf lettuce than lowering light intensity and increasing the fraction of blue light.\n                  <\/jats:p>","DOI":"10.3389\/fpls.2026.1699278","type":"journal-article","created":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T06:40:47Z","timestamp":1771483247000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["While end-of-production sole-source lighting at a moderate intensity increased nutrient, water-soluble vitamin, and carotenoid content, the anthocyanin concentration of red leaf lettuce decreased"],"prefix":"10.3389","volume":"17","author":[{"given":"Devin","family":"Brewer","sequence":"first","affiliation":[{"name":"Department of Horticulture, Michigan State University","place":["East Lansing, MI, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kellie J.","family":"Walters","sequence":"additional","affiliation":[{"name":"Department of Plant Sciences, University of Tennessee","place":["Knoxville, TN, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer K.","family":"Boldt","sequence":"additional","affiliation":[{"name":"United States Department of Agriculture - Agricultural Research Service Application Technology Research Unit","place":["Toledo, OH, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roberto G.","family":"Lopez","sequence":"additional","affiliation":[{"name":"Department of Horticulture, Michigan State University","place":["East Lansing, MI, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,19]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1016\/j.scienta.2018.02.065","article-title":"Light emitting diodes (LEDs) affect morphological, physiological, and phytochemical characteristics of pomegranate seedlings","volume":"234","author":"Bantis","year":"2018","journal-title":"Sci. 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