title: Molecular cloning and functional identification of (+)-delta-cadinene-8-hydroxylase, a cytochrome P450 mono-oxygenase (CYP706B1) of cotton sesquiterpene biosynthesis.
abstract: In cotton, gossypol and related sesquiterpene aldehydes are present in the glands of aerial tissues and in epidermal cells of roots. A cytochrome P450 was found to be expressed in aerial tissues of glanded cotton cultivars, but not or at an extremely low level in the aerial tissues of a glandless cultivar. Its cDNA was then isolated from Gossypium arboreum L. After expression in Saccharomyces cerevisiae, the P450 was found to catalyse the hydroxylation of (+)-delta-cadinene, forming 8-hydroxy-(+)-delta-cadinene. This P450 mono-oxygenase has been classified as CYP706B1, and is the first member of the CYP706 family for which a function has been determined. Sesquiterpene aldehydes and CYP706B1 transcripts were detected in roots of both the glanded and glandless cultivars and in aerial tissues of the glanded cultivar. In suspension cultured cells of G. arboreum, elicitors prepared from the phytopathogenic fungus Verticillium dahliae caused a dramatic induction of CYP706B1 expression. The expression pattern of CYP706B1 and the position at which it hydroxylates (+)-delta-cadinene suggest that it catalyses an early step in gossypol biosynthesis. Southern blotting revealed a single copy of CYP706B1 in the genome of G. arboreum. CYP706B1 holds good potential for manipulation of gossypol levels in cottonseed via genetic engineering.
authors.affiliation: National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, People's Republic of China.
authors.forename: P
authors.initials: P
authors.lastname: Luo
authors.forename: Y H
authors.initials: YH
authors.lastname: Wang
authors.forename: G D
authors.initials: GD
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Essenberg
authors.forename: X Y
authors.initials: XY
authors.lastname: Chen
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D007535:Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D012717:Sesquiterpenes; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D007535:Isomerases