title: Analysis of flavonoids and the flavonoid structural genes in brown fiber of upland cotton.
abstract: BACKGROUND
  As a result of changing consumer preferences, cotton (Gossypium Hirsutum L.) from varieties with naturally colored fibers is becoming increasingly sought after in the textile industry. The molecular mechanisms leading to colored fiber development are still largely unknown, although it is expected that the color is derived from flavanoids.
  
  
  METHODS
  Firstly, four key genes of the flavonoid biosynthetic pathway in cotton (GhC4H, GhCHS, GhF3'H, and GhF3'5'H) were cloned and studied their expression profiles during the development of brown- and white cotton fibers by QRT-PCR. And then, the concentrations of four components of the flavonoid biosynthetic pathway, naringenin, quercetin, kaempferol and myricetin in brown- and white fibers were analyzed at different developmental stages by HPLC.
  
  
  RESULTS
  The predicted proteins of the four flavonoid structural genes corresponding to these genes exhibit strong sequence similarity to their counterparts in various plant species. Transcript levels for all four genes were considerably higher in developing brown fibers than in white fibers from a near isogenic line (NIL). The contents of four flavonoids (naringenin, quercetin, kaempferol and myricetin) were significantly higher in brown than in white fibers and corresponding to the biosynthetic gene expression levels.
  
  
  CONCLUSIONS
  Flavonoid structural gene expression and flavonoid metabolism are important in the development of pigmentation in brown cotton fibers.
authors.affiliation: The Key Laboratory of Oasis Eco-agriculture, Agriculture College of Shihezi University, Shihezi, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Feng
authors.forename: Xinhui
authors.initials: X
authors.lastname: Tian
authors.forename: Yongchang
authors.initials: Y
authors.lastname: Liu
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Li
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Brian Joseph
authors.initials: BJ
authors.lastname: Jones
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Sun
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
mesh_terms: D000217:Acyltransferases / Q000737:chemistry / Q000145:classification / Q000235:genetics; D000595:Amino Acid Sequence; D053898:Biosynthetic Pathways; D003001:Cloning, Molecular; D032561:Cotton Fiber; D003577:Cytochrome P-450 Enzyme System / Q000145:classification / Q000235:genetics; D005419:Flavonoids / Q000096:biosynthesis* / Q000737:chemistry*; D015870:Gene Expression; D020869:Gene Expression Profiling; D003368:Gossypium / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D005419:Flavonoids; D010940:Plant Proteins; D003577:Cytochrome P-450 Enzyme System; D000217:Acyltransferases; C020141:flavanone synthetase