title: Comparative gene expression analysis in a highly anthocyanin pigmented mutant of colorless chrysanthemum.
abstract: In this study, we investigated differentially expressed genes between the original chrysanthemum cultivar 'Argus' with white flower color and its gamma-ray irradiated mutant 'ARTI-purple' with purple flower color. The expression levels of anthocyanin biosynthetic genes were not associated with anthocyanin accumulations of Argus and ARTI-purple. Expressed sequence tags (ESTs) analysis was performed to identify a novel cDNAs encoding enzymes of specific plant metabolic pathways and the biological effects of gamma-ray mutation through alterations in expression in each flower. A total of 796 unigenes were isolated from chrysanthemum ray florets. These unigenes were functionally classified using gene ontologies and tentative pathway associations were established to 99 sequences in the Kyoto encyclopedia of genes and genomes. The expressions of the isolated ESTs were screened by cDNA dot blot hybridization. Seven differentially expressed genes were identified as being involved in carbohydrate and lipid metabolic pathways and five as transcription factor or signal transduction genes. Of particular note, decreased expression of CmMYB1 was identified at the 'ARTI-purple'. The CmMYB1 shared high similarity with AtMYB4 and AtMYBL2 which is a negative regulator of anthocyanin and flavonol accumulation. Furthermore, two genes involved in lipid metabolism, enoyl-ACP reductase and [acyl-carrier-protein] S-malonyltransferase, were decreased in the 'ARTI-purple' flower. Our results suggest that the purple pigmentation of the 'ARTI-purple' is not just dependent on the expression of anthocyanin synthesis genes, and that the pigmentation may also affect other metabolic processing and the plant cell environment.
authors.affiliation: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, 580-185, Korea. sungssy@gmail.com
authors.forename: Sang Yeop
authors.initials: SY
authors.lastname: Sung
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Vijayanand
authors.initials: V
authors.lastname: Velusamy
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Bo-Keun
authors.initials: BK
authors.lastname: Ha
authors.forename: Jin-Baek
authors.initials: JB
authors.lastname: Kim
authors.forename: Si-Yong
authors.initials: SY
authors.lastname: Kang
authors.forename: Hong Gi
authors.initials: HG
authors.lastname: Kim
authors.forename: Dong Sub
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000872:Anthocyanins / Q000378:metabolism*; D031202:Chrysanthemum / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016000:Cluster Analysis; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D015723:Gene Library; D016695:Glycosyltransferases / Q000235:genetics*; D015151:Immunoblotting; D008957:Models, Genetic; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D017931:DNA Primers; D014157:Transcription Factors; D016695:Glycosyltransferases