title: Riboflavin accumulation and molecular characterization of cDNAs encoding bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone 4-phosphate synthase, lumazine synthase, and riboflavin synthase in different organs of Lycium chinense plant.
abstract: Riboflavin (vitamin B2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide-essential cofactors for a wide variety of enzymes involving in numerous metabolic processes. In this study, a partial-length cDNA encoding bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone-4-phosphate synthase (LcRIBA), 2 full-length cDNAs encoding lumazine synthase (LcLS1 and LcLS2), and a full-length cDNA encoding riboflavin synthase (LcRS) were isolated from Lycium chinense, an important traditional medicinal plant. Sequence analyses showed that these genes exhibited high identities with their orthologous genes as well as having the same common features related to plant riboflavin biosynthetic genes. LcRIBA, like other plant RIBAs, contained a DHBPS region in its N terminus and a GCHII region in its C-terminal part. LcLSs and LcRS carried an N-terminal extension found in plant riboflavin biosynthetic genes unlike the orthologous microbial genes. Quantitative real-time polymerase chain reaction analysis showed that 4 riboflavin biosynthetic genes were constitutively expressed in all organs examined of L. chinense plants with the highest expression levels found in the leaves or red fruits. LcRIBA, which catalyzes 2 initial reactions in riboflavin biosynthetic pathway, was the highest transcript in the leaves, and hence, the richest content of riboflavin was detected in this organ. Our study might provide the basis for investigating the contribution of riboflavin in diverse biological activities of L. chinense and may facilitate the metabolic engineering of vitamin B2 in crop plants.
authors.affiliation: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. tuan_pham_6885@yahoo.com.
authors.forename: Pham Anh
authors.initials: PA
authors.lastname: Tuan
authors.affiliation: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. zhaoshicheng@msn.com.
authors.forename: Shicheng
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon 406-772, Korea. kjkpj@incheon.ac.kr.
authors.forename: Jae Kwang
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. yeonbokkim@hanmail.net.
authors.forename: Yeon Bok
authors.initials: YB
authors.lastname: Kim
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. yifan85831647@sina.com.
authors.forename: Jingli
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. chli0@163.com.
authors.forename: Cheng Hao
authors.initials: CH
authors.lastname: Li
authors.affiliation: Department of Bio-Environmental Chemistry, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, Korea. kimsunju@cnu.ac.kr.
authors.forename: Sun-Ju
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia. mvalanarasu@gmail.com.
authors.forename: Mariadhas Valan
authors.initials: MV
authors.lastname: Arasu
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia. mvalanarasu@gmail.com.
authors.forename: Naif Abdullah
authors.initials: NA
authors.lastname: Al-Dhabi
authors.affiliation: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. supark@cnu.ac.kr.
authors.forename: Sang Un
authors.initials: SU
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D044822:Biodiversity; D018076:DNA, Complementary / Q000235:genetics*; D006136:GTP Cyclohydrolase / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant / Q000235:genetics; D032305:Lycium / Q000235:genetics* / Q000378:metabolism; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D010946:Plants, Medicinal / Q000235:genetics / Q000378:metabolism; D012256:Riboflavin / Q000235:genetics* / Q000378:metabolism*; D012258:Riboflavin Synthase / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D013403:Sugar Phosphates / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D009097:Multienzyme Complexes; D013403:Sugar Phosphates; C066494:3,4-dihydroxy-2-butanone-4-phosphate; C044822:6,7-dimethyl-8-ribityllumazine synthase; D012258:Riboflavin Synthase; D006136:GTP Cyclohydrolase; D010453:Peptide Synthases; D012256:Riboflavin