title: Roles of MPBQ-MT in Promoting α/γ-Tocopherol Production and Photosynthesis under High Light in Lettuce.
abstract: 2-methyl-6-phytyl-1, 4-benzoquinol methyltransferase (MPBQ-MT) is a vital enzyme catalyzing a key methylation step in both α/γ-tocopherol and plastoquinone biosynthetic pathway. In this study, the gene encoding MPBQ-MT was isolated from lettuce (Lactuca sativa) by rapid amplification of cDNA ends (RACE), named LsMT. Overexpression of LsMT in lettuce brought about a significant increase of α- and γ-tocopherol contents with a reduction of phylloquinone (vitamin K1) content, suggesting a competition for a common substrate phytyl diphosphate (PDP) between the two biosynthetic pathways. Besides, overexpression of LsMT significantly increased plastoquinone (PQ) level. The increase of tocopherol and plastoquinone levels by LsMT overexpression conduced to the improvement of plants' tolerance and photosynthesis under high light stress, by directing excessive light energy toward photosynthetic production rather than toward generation of more photooxidative damage. These findings suggest that the role and function of MPBQ-MT can be further explored for enhancing vitamin E value, strengthening photosynthesis and phototolerance under high light in plants.
authors: Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
authors: Yueli
authors: Y
authors: Tang
authors: Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
authors: Xueqing
authors: X
authors: Fu
authors: Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
authors: Qian
authors: Q
authors: Shen
authors: Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
authors: Kexuan
authors: K
authors: Tang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology; D002241:Carbohydrates / Q000737:chemistry; D002734:Chlorophyll / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D011756:Diphosphates / Q000737:chemistry; D005091:Exons; D018506:Gene Expression Regulation, Plant; D007438:Introns; D018545:Lactuca / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D008027:Light; D008780:Methyltransferases / Q000096:biosynthesis / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry; D010788:Photosynthesis; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants; D030821:Plants, Genetically Modified / Q000201:enzymology; D010971:Plastoquinone / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013696:Temperature; D019076:Transgenes; D014810:Vitamin E / Q000378:metabolism; D010837:Vitamin K 1 / Q000737:chemistry / Q000378:metabolism; D024502:alpha-Tocopherol / Q000737:chemistry*; D024504:gamma-Tocopherol / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D011756:Diphosphates; D010940:Plant Proteins; C529546:phytyl diphosphate; D014810:Vitamin E; D002734:Chlorophyll; D010837:Vitamin K 1; D024504:gamma-Tocopherol; C447422:2-methyl-6-phytylbenzoquinone methyltransferase; D008780:Methyltransferases; D024502:alpha-Tocopherol; D010971:Plastoquinone; D010100:Oxygen