title: Transcriptomics-based identification of WRKY genes and characterization of a salt and hormone-responsive PgWRKY1 gene in Panax ginseng.
abstract: WRKY proteins belong to a transcription factor (TF) family and play dynamic roles in many plant processes, including plant responses to abiotic and biotic stresses, as well as secondary metabolism. However, no WRKY gene in Panax ginseng C.A. Meyer has been reported to date. In this study, a number of WRKY unigenes from methyl jasmonate (MeJA)-treated adventitious root transcriptome of this species were identified using next-generation sequencing technology. A total of 48 promising WRKY unigenes encoding WRKY proteins were obtained by eliminating wrong and incomplete open reading frame (ORF). Phylogenetic analysis reveals 48 WRKY TFs, including 11 Group I, 36 Group II, and 1 Group III. Moreover, one MeJA-responsive unigene designated as PgWRKY1 was cloned and characterized. It contains an entire ORF of 1077 bp and encodes a polypeptide of 358 amino acid residues. The PgWRKY1 protein contains a single WRKY domain consisting of a conserved amino acid sequence motif WRKYGQK and a C2H2-type zinc-finger motif belonging to WRKY subgroup II-d. Subcellular localization of PgWRKY1-GFP fusion protein in onion and tobacco epidermis cells revealed that PgWRKY1 was exclusively present in the nucleus. Quantitative real-time polymerase chain reaction analysis demonstrated that the expression of PgWRKY1 was relatively higher in roots and lateral roots compared with leaves, stems, and seeds. Importantly, PgWRKY1 expression was significantly induced by salicylic acid, abscisic acid, and NaCl, but downregulated by MeJA treatment. These results suggested that PgWRKY1 might be a multiple stress-inducible gene responding to hormones and salt stresses.
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Nuruzzaman
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Hongzhe
authors.initials: H
authors.lastname: Cao
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Xiu
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Tiao
authors.initials: T
authors.lastname: Luo
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Jijia
authors.initials: J
authors.lastname: Li
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Chen
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China.
authors.forename: Junli
authors.initials: J
authors.lastname: Luo
authors.affiliation: Molecular Biology Research Center, State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, China luozhiyong@csu.edu.cn.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Luo
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology; D017343:Genes, Plant; D008958:Models, Molecular; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000494:pharmacology; D005894:Panax / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014157:Transcription Factors; D012965:Sodium Chloride; C072239:methyl jasmonate
keywords: Panax ginseng; WRKY transcription factor; abiotic stress; transcriptome