title: De novo transcriptome assembly and characterization of nine tissues of Lonicera japonica to identify potential candidate genes involved in chlorogenic acid, luteolosides, and secoiridoid biosynthesis pathways.
abstract: Lonicera japonica is one of the most important medicinal plants with applications in traditional Chinese and Japanese medicine for thousands of years. Extensive studies on the constituents of L. japonica extracts have revealed an accumulation of pharmaceutically active metabolite classes, such as chlorogenic acid, luteolin and other flavonoids, and secoiridoids, which impart characteristic medicinal properties. Despite being a rich source of pharmaceutically active metabolites, little is known about the biosynthetic enzymes involved, and their expression profile across different tissues of L. japonica. In this study, we performed de novo transcriptome assembly for L. japonica, representing transcripts from nine different tissues. A total of 22 Gbps clean RNA-seq reads from nine tissues of L. japonica were used, resulting in 243,185 unigenes, with 99,938 unigenes annotated based on a homology search using blastx against the NCBI-nr protein database. Unsupervised principal component analysis and correlation studies using transcript expression data from all nine tissues of L. japonica showed relationships between tissues, explaining their association at different developmental stages. Homologs for all genes associated with chlorogenic acid, luteolin, and secoiridoid biosynthesis pathways were identified in the L. japonica transcriptome assembly. Expression of unigenes associated with chlorogenic acid was enriched in stems and leaf-2, unigenes from luteolin were enriched in stems and flowers, while unigenes from secoiridoid metabolic pathways were enriched in leaf-1 and shoot apex. Our results showed that different tissues of L. japonica are enriched with sets of unigenes associated with specific pharmaceutically important metabolic pathways and, therefore, possess unique medicinal properties. The present study will serve as a resource for future attempts for functional characterization of enzyme coding genes within key metabolic processes.
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan. amit.rai@chiba-u.jp.
authors.forename: Amit
authors.initials: A
authors.lastname: Rai
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kamochi
authors.affiliation: Kazusa DNA Research Institute, Chiba, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.
authors.forename: Michimi
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Medical Mycology Research Center, Chiba University, Chiba, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Hatada
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Saito
authors.affiliation: Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan. mamiy@faculty.chiba-u.jp.
authors.forename: Mami
authors.initials: M
authors.lastname: Yamazaki
mesh_terms: D002726:Chlorogenic Acid / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D039823:Iridoids / Q000378:metabolism*; D031239:Lonicera / Q000737:chemistry*; D047311:Luteolin / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D059467:Transcriptome / Q000235:genetics*
chemical_list: D005960:Glucosides; D039823:Iridoids; D002726:Chlorogenic Acid; C066408:luteolin-7-glucoside; D047311:Luteolin
keywords: Chlorogenic acid; De novo transcriptome assembly; Luteolosides; Secoiridoid