title: The identification of CVP1 reveals a role for sterols in vascular patterning.
abstract: Vascular cell axialization refers to the uniform alignment of vascular strands. In the Arabidopsis cotyledon vascular pattern1 (cvp1) mutant, vascular cells are not arranged in parallel files and are misshapen, suggesting that CVP1 has a role in promoting vascular cell polarity and alignment. Characterization of an allelic series of cvp1 mutations revealed additional functions of CVP1 in organ expansion and elongation. We identified CVP1 and found that it encodes STEROL METHYLTRANSFERASE2 (SMT2), an enzyme in the sterol biosynthetic pathway. SMT2 and the functionally redundant SMT3 act at a branch point in the pathway that mediates sterol and brassinosteroid levels. The SMT2 gene is expressed in a number of developing organs and is regulated by various hormones. As predicted from SMT2 enzymatic activity, the precursors to brassinosteroid are increased at the expense of sterols in cvp1 mutants, identifying a role for sterols in vascular cell polarization and axialization.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Francine M
authors.initials: FM
authors.lastname: Carland
authors.forename: Shozo
authors.initials: S
authors.lastname: Fujioka
authors.forename: Suguru
authors.initials: S
authors.lastname: Takatsuto
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshida
authors.forename: Timothy
authors.initials: T
authors.lastname: Nelson
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology; D060406:Brassinosteroids; D002777:Cholestanols / Q000037:antagonists & inhibitors / Q000378:metabolism; D003001:Cloning, Molecular; D018548:Cotyledon / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010840:Phytosterols / Q000096:biosynthesis* / Q000737:chemistry; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013260:Steroids, Heterocyclic / Q000037:antagonists & inhibitors / Q000378:metabolism; D014230:Triazoles / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols; D010840:Phytosterols; D012333:RNA, Messenger; D013260:Steroids, Heterocyclic; D014230:Triazoles; C409822:24-methylene-lophenol-C24-methyltransferase; D008780:Methyltransferases; C585557:SMT3 protein, Arabidopsis; C412342:brassinazole; C023623:brassinolide