title: The Phytol Phosphorylation Pathway Is Essential for the Biosynthesis of Phylloquinone, which Is Required for Photosystem I Stability in Arabidopsis.
abstract: Phytyl-diphosphate, which provides phytyl moieties as a common substrate in both tocopherol and phylloquinone biosynthesis, derives from de novo isoprenoid biosynthesis or a salvage pathway via phytol phosphorylation. However, very little is known about the role and origin of the phytyl moiety for phylloquinone biosynthesis. Since VTE6, a phytyl-phosphate kinase, is a key enzyme for phytol phosphorylation, we characterized Arabidopsis vte6 mutants to gain insight into the roles of phytyl moieties in phylloquinone biosynthesis and of phylloquinone in photosystem I (PSI) biogenesis. The VTE6 knockout mutants vte6-1 and vte6-2 lacked detectable phylloquinone, whereas the phylloquinone content in the VTE6 knockdown mutant vte6-3 was 90% lower than that in wild-type. In vte6 mutants, PSI function was impaired and accumulation of the PSI complex was defective. The PSI core subunits PsaA/B were efficiently synthesized and assembled into the PSI complex in vte6-3. However, the degradation rate of PSI subunits in the assembled PSI complex was more rapid in vte6-3 than in wild-type. In vte6-3, PSI was more susceptible to high-light damage than in wild-type. Our results provide the first genetic evidence that the phytol phosphorylation pathway is essential for phylloquinone biosynthesis, and that phylloquinone is required for PSI complex stability.
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Li
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Aihong
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Jiang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Zhipan
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Huixia
authors.initials: H
authors.lastname: Yang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Qin
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Shunhua
authors.initials: S
authors.lastname: Ding
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Qingtao
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wen
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; National Center for Plant Gene Research, Beijing 100093, China. Electronic address: lucm@ibcas.ac.cn.
authors.forename: Congming
authors.initials: C
authors.lastname: Lu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques; D008027:Light; D009154:Mutation; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D045331:Photosystem I Protein Complex / Q000378:metabolism* / Q000528:radiation effects; D010836:Phytol / Q000378:metabolism*; D055550:Protein Stability; D010837:Vitamin K 1 / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D045331:Photosystem I Protein Complex; D010836:Phytol; D010837:Vitamin K 1; D017853:Phosphotransferases (Alcohol Group Acceptor); C000623375:VTE6 protein, Arabidopsis
keywords: PSI stability; VTE6; phylloquinone; phytol phosphorylation