l-Tryptophan synergistically increased carotenoid accumulation with blue light in maize (Zea mays L.) sprouts

Nan Xiang; Xitao Qi; Jianguang Hu; Siyun Wang; Xinbo Guo

doi:10.1016/j.fochms.2023.100161

l-Tryptophan synergistically increased carotenoid accumulation with blue light in maize (Zea mays L.) sprouts

Food Chem (Oxf). 2023 Jan 9:6:100161. doi: 10.1016/j.fochms.2023.100161. eCollection 2023 Jul 30.

Authors

Nan Xiang¹, Xitao Qi², Jianguang Hu², Siyun Wang³, Xinbo Guo¹

Affiliations

¹ School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Engineering Research Center of Starch and Vegetable Protein Processing Ministry of Education, Research Institute for Food Nutrition and Human Health, South China University of Technology, Guangzhou, China.
² Key Laboratory of Crops Genetics Improvement of Guangdong Province, Crop Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
³ Department of Food, Nutrition, and Health, University of British Columbia, Vancouver, BC, Canada.

Abstract

In the present study, l-tryptophan was applied in combination with blue light to modulate carotenoid biosynthesis in maize sprouts. The profiles of carotenoids, chlorophylls, and relative genes in carotenoid biosynthesis and light signaling pathways were studied. l-tryptophan and blue light both promoted the accumulation of carotenoids, and their combination further increased carotenoid content by 120%. l-tryptophan exerted auxin-like effects and stimulated PSY expression in blue light exposure maize sprouts, resulting in increased α- and β- carotenes. l-tryptophan could also play a photoprotective role through the xanthophyll cycle under blue light. In addition, CRY in the light signaling pathway was critical for carotenoid biosynthesis. These findings provide new insights into the regulation of carotenoid biosynthesis and l-tryptophan could be used in conjunction with blue light to fortify carotenoids in maize sprouts.

Keywords: Blue light; CHYB, beta-carotene 3-hydroxylase; CHYE, carotenoid epsilon hydroxylase; COP1, constitutive photomorphogenic 1; CRTISO, carotenoid isomerase; CRY, cryptochrome; Carotenoid; FAD, flavin adenine dinucleotide; FKF1, flavin-binding kelch repeat F-box protein 1; GGDP, Geranylgeranyl diphosphate; HPLC, high-performance liquid chromatography; HY5, protein long hypocotyl 5; LCYB, lycopene beta-cyclase; LCYE, lycopene epsilon-cyclase; LUT5, LUTEIN DEFICIENT 5; Light signal; Maize sprouts; NXD1, NEOXANTHIN-DEFICIENT 1; NXS, neoxanthin synthase; OCP, Orange Carotenoid Protein; PDS, 15-cis-phytoene desaturase; PHOT1, phototropin 1; PIF, phytochrome-interacting factor; PSY, 15-cis-phytoene synthase; VDE, violaxanthin de-epoxidase; Z-ISO, zeta-carotene isomerase; ZDS, zeta-carotene desaturase; ZEP, zeaxanthin epoxidase; l-Tryptophan.