title: Identification of laticifer-specific genes and their promoter regions from a natural rubber producing plant Hevea brasiliensis.
abstract: Latex, the milky cytoplasm of highly differentiated cells called laticifers, from Hevea brasiliensis is a key source of commercial natural rubber production. One way to enhance natural rubber production would be to express genes involved in natural rubber biosynthesis by a laticifer-specific overexpression system. As a first step to identify promoters which could regulate the laticifer-specific expression, we identified random clones from a cDNA library of H. brasiliensis latex, resulting in 4325 expressed sequence tags (ESTs) assembled into 1308 unigenes (692 contigs and 617 singletons). Quantitative analyses of the transcription levels of high redundancy clones in the ESTs revealed genes highly and predominantly expressed in laticifers, such as Rubber Elongation Factor (REF), Small Rubber Particle Protein and putative protease inhibitor proteins. HRT1 and HRT2, cis-prenyltransferases involved in rubber biosynthesis, was also expressed predominantly in laticifers, although these transcript levels were 80-fold lower than that of REF. The 5'-upstream regions of these laticifer-specific genes were cloned and analyzed in silico, revealing seven common motifs consisting of eight bases. Furthermore, transcription factors specifically expressed in laticifers were also identified. The common motifs in the laticifer-specific genes and the laticifer-specific transcription factors are potentially involved in the regulation of gene expression in laticifers.
authors.affiliation: Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan. Electronic address: takahasi@seika.che.tohoku.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takayama
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ogata
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Sakurai
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan; Research and Development Institute, Thaksin University, Songkhla, Thailand.
authors.forename: Kasem
authors.initials: K
authors.lastname: Asawatreratanakul
authors.affiliation: Department of Biochemistry, Mahidol University, Bangkok, Thailand.
authors.forename: Dhirayos
authors.initials: D
authors.lastname: Wititsuwannakul
authors.affiliation: Department of Biochemistry, Prince of Songkla University, Hat-Yai, Thailand.
authors.forename: Rapepun
authors.initials: R
authors.lastname: Wititsuwannakul
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shibata
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Tanetoshi
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004122:Dimethylallyltranstransferase / Q000378:metabolism; D020224:Expressed Sequence Tags; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant; D028482:Hevea / Q000235:genetics* / Q000378:metabolism; D007840:Latex / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D059828:Plant Cells / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012408:Rubber; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D007840:Latex; D010940:Plant Proteins; D014157:Transcription Factors; D012408:Rubber; D004122:Dimethylallyltranstransferase
keywords: Expressed sequence tag; Hevea brasiliensis; Latex; Laticifer; Natural rubber; cis-Prenyltransferase