title: Isolation and promoter analysis of a chalcone synthase gene PtrCHS4 from Populus trichocarpa.
abstract: As perennial plants, Populus species are constantly exposed to environmental stresses, such as wounding and pathogen attack, which lead to production of compounds including lignin, flavonoids and phytoalexins. Chalcone synthase (CHS) is a key enzyme in the flavonoid biosynthesis pathway. In this study, a cDNA clone encoding CHS was isolated from Populus trichocarpa by reverse transcription-polymerase chain reaction (RT-PCR). The full-length cDNA, named PtrCHS4, was 1,314 bp with a 1,173 bp open reading frame that corresponded to a deduced protein of 391 amino acid residues. Multiple sequence alignments showed that PtrCHS4 shared high homology with CHS proteins from other plants. Phylogenetic analysis revealed that PtrCHS4 was most closely related to PhCHS from Petunia hybrida and NaCHS from Nicotiana attenuata. Semi-quantitative RT-PCR analysis identified that the PtrCHS4 gene was abundantly expressed in the leaves and stems, while its expression was drastically reduced in the roots. Transcript abundance of PtrCHS4 was stimulated by 2.5-fold within 24 h of wounding treatment. Promoter analysis confirmed that the PtrCHS4 promoter was capable of directing expression of the GUS reporter in both wounded and unwounded leaves of transgenic Chinese white poplar (P. tomentosa Carr.), indicating that the PtrCHS4 promoter is systemically responsive to wounding stimuli. Furthermore, promoter deletion analysis showed that the proximal 1,592 bp from the transcription start site were required for promoter activation by jasmonic acid and the -1,096 to -148 region was proved to be necessary for establishing wound-induced pattern of expression.
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, State Key Laboratory of Eco-environment and Bio-resource of Three Gorges Reservoir Region, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Sun
authors.forename: Qiaoyan
authors.initials: Q
authors.lastname: Tian
authors.forename: Li
authors.initials: L
authors.lastname: Yuan
authors.forename: Yuanzhong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.forename: Shaohu
authors.initials: S
authors.lastname: Tang
authors.forename: Keming
authors.initials: K
authors.lastname: Luo
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018506:Gene Expression Regulation, Plant; D050939:Gene Fusion; D017343:Genes, Plant; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000494:pharmacology; D010802:Phylogeny; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D032107:Populus / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein / Q000379:methods; D013312:Stress, Physiological; D015533:Transcriptional Activation; D014170:Transformation, Genetic; D019076:Transgenes
chemical_list: D003517:Cyclopentanes; D018076:DNA, Complementary; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; D000217:Acyltransferases; C020141:flavanone synthetase