title: Effect of an Introduced Phytoene Synthase Gene Expression on Carotenoid Biosynthesis in the Marine Diatom Phaeodactylum tricornutum.
abstract: Carotenoids exert beneficial effects on human health through their excellent antioxidant activity. To increase carotenoid productivity in the marine Pennales Phaeodactylum tricornutum, we genetically engineered the phytoene synthase gene (psy) to improve expression because RNA-sequencing analysis has suggested that the expression level of psy is lower than other enzyme-encoding genes that are involved in the carotenoid biosynthetic pathway. We isolated psy from P. tricornutum, and this gene was fused with the enhanced green fluorescent protein gene to detect psy expression. After transformation using the microparticle bombardment technique, we obtained several P. tricornutum transformants and confirmed psy expression in their plastids. We investigated the amounts of PSY mRNA and carotenoids, such as fucoxanthin and β-carotene, at different growth phases. The introduction of psy increased the fucoxanthin content of a transformants by approximately 1.45-fold relative to the levels in the wild-type diatom. However, some transformants failed to show a significant increase in the carotenoid content relative to that of the wild-type diatom. We also found that the amount of PSY mRNA at log phase might contribute to the increase in carotenoids in the transformants at stationary phase.
authors: Laboratory of Aquatic Environmental Science, Faculty of Agriculture, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan. kadono-takashi@kochi-u.ac.jp.
authors: Takashi
authors: T
authors: Kadono
authors: The United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan. s10dre05@s.kochi-u.ac.jp.
authors: Nozomu
authors: N
authors: Kira
authors: Euglena Co., Ltd., 4th Floor, Yokohama Leading Venture Plaza, 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan. suzuki@euglena.jp.
authors: Kengo
authors: K
authors: Suzuki
authors: Euglena Co., Ltd., 4th Floor, Yokohama Leading Venture Plaza, 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan. iwata@euglena.jp.
authors: Osamu
authors: O
authors: Iwata
authors: School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan. ohama.takeshi@kochi-tech.ac.jp.
authors: Takeshi
authors: T
authors: Ohama
authors: Department of Aquatic Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. aokada@mail.ecc.u-tokyo.ac.jp.
authors: Shigeru
authors: S
authors: Okada
authors: Laboratory of Aquatic Environmental Science, Faculty of Agriculture, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan. aquariumuirauqa@gmail.com.
authors: Tomohiro
authors: T
authors: Nishimura
authors: Synthetic Organic Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. mai.akakabe@riken.jp.
authors: Mai
authors: M
authors: Akakabe
authors: Science Research Center, Kochi University, Oko-cho Kohasu, Nankoku, Kochi 783-8506, Japan. mtsuda@kochi-u.ac.jp.|Center for Advanced Marine Core Research, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan. mtsuda@kochi-u.ac.jp.
authors: Masashi
authors: M
authors: Tsuda
authors: Laboratory of Aquatic Environmental Science, Faculty of Agriculture, Kochi University, Otsu-200, Monobe, Nankoku, Kochi 783-8502, Japan. madachi@kochi-u.ac.jp.
authors: Masao
authors: M
authors: Adachi
mesh_terms: D059001:Aquatic Organisms / Q000235:genetics*; D053898:Biosynthetic Pathways / Q000235:genetics*; D002338:Carotenoids / Q000096:biosynthesis* / Q000235:genetics; D017377:Diatoms / Q000235:genetics*; D015870:Gene Expression / Q000235:genetics*; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase / Q000235:genetics*; D018087:Plastids / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D024341:Xanthophylls / Q000235:genetics; D019207:beta Carotene / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D024341:Xanthophylls; D019207:beta Carotene; C025164:fucoxanthin; D002338:Carotenoids; C100185:(all-E) phytoene; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase
keywords: PSY; carotenoid; marine diatom; microalgae; transformation