title: Arabidopsis transcriptome analysis reveals key roles of melatonin in plant defense systems.
abstract: Melatonin is a ubiquitous molecule and exists across kingdoms including plant species. Studies on melatonin in plants have mainly focused on its physiological influence on growth and development, and on its biosynthesis. Much less attention has been drawn to its affect on genome-wide gene expression. To comprehensively investigate the role(s) of melatonin at the genomics level, we utilized mRNA-seq technology to analyze Arabidopsis plants subjected to a 16-hour 100 pM (low) and 1 mM (high) melatonin treatment. The expression profiles were analyzed to identify differentially expressed genes. 100 pM melatonin treatment significantly affected the expression of only 81 genes with 51 down-regulated and 30 up-regulated. However, 1 mM melatonin significantly altered 1308 genes with 566 up-regulated and 742 down-regulated. Not all genes altered by low melatonin were affected by high melatonin, indicating different roles of melatonin in regulation of plant growth and development under low and high concentrations. Furthermore, a large number of genes altered by melatonin were involved in plant stress defense. Transcript levels for many stress receptors, kinases, and stress-associated calcium signals were up-regulated. The majority of transcription factors identified were also involved in plant stress defense. Additionally, most identified genes in ABA, ET, SA and JA pathways were up-regulated, while genes pertaining to auxin responses and signaling, peroxidases, and those associated with cell wall synthesis and modifications were mostly down-regulated. Our results indicate critical roles of melatonin in plant defense against various environmental stresses, and provide a framework for functional analysis of genes in melatonin-mediated signaling pathways.
authors.affiliation: Agriculture Research Station, Virginia State University, Petersburg, Virginia, United States of America.
authors.forename: Sarah
authors.initials: S
authors.lastname: Weeda
authors.affiliation: College of Agriculture and Biotechnology, China Agricultural University, Beijing, P. R. China.
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Tianjin Crop Science Institute, Tianjin Academy of Agricultural Science, Tianjin, P. R. China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Virginia State University, Petersburg, Virginia, United States of America.
authors.forename: Grace
authors.initials: G
authors.lastname: Ndip
authors.affiliation: College of Agriculture and Biotechnology, China Agricultural University, Beijing, P. R. China.
authors.forename: Yangdong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Center of the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Buck
authors.affiliation: Tianjin Crop Science Institute, Tianjin Academy of Agricultural Science, Tianjin, P. R. China.
authors.forename: Conggui
authors.initials: C
authors.lastname: Fu
authors.affiliation: Agriculture Research Station, Virginia State University, Petersburg, Virginia, United States of America.
authors.forename: Shuxin
authors.initials: S
authors.lastname: Ren
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008550:Melatonin / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D059467:Transcriptome / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D008550:Melatonin