This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/5/1473    most recent tpc.106.045948v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Morant, M. Articles by Bak, S. Search for Related Content PubMed PubMed Citation Articles by Morant, M. Articles by Bak, S. Agricola Articles by Morant, M. Articles by Bak, S.

CYP703 Is an Ancient Cytochrome P450 in Land Plants Catalyzing in-Chain Hydroxylation of Lauric Acid to Provide Building Blocks for Sporopollenin Synthesis in Pollen^[W]

^a Plant Biochemistry Laboratory, Department of Plant Biology and Center for Molecular Plant Physiology, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Copenhagen, Denmark
^b Departments of Plant Metabolic Responses and Plant Isoprenoids, Botanic Institute, Louis Pasteur University, 67083 Strasbourg Cedex, France

¹ To whom correspondence should be addressed. E-mail bak{at}life.ku.dk; fax 45-35-28-33-33.

CYP703 is a cytochrome P450 family specific to land plants. Typically, each plant species contains a single CYP703. Arabidopsis thaliana CYP703A2 is expressed in the anthers of developing flowers. Expression is initiated at the tetrad stage and restricted to microspores and to the tapetum cell layer. Arabidopsis CYP703A2 knockout lines showed impaired pollen development and a partial male-sterile phenotype. Scanning electron and transmission electron microscopy of pollen from the knockout plants showed impaired pollen wall development with absence of exine. The fluorescent layer around the pollen grains ascribed to the presence of phenylpropanoid units in sporopollenin was absent in the CYP703A2 knockout lines. Heterologous expression of CYP703A2 in yeast cells demonstrated that CYP703 catalyzes the conversion of medium-chain saturated fatty acids to the corresponding monohydroxylated fatty acids, with a preferential hydroxylation of lauric acid at the C-7 position. Incubation of recombinant CYP703 with methanol extracts from developing flowers confirmed that lauric acid and in-chain hydroxy lauric acids are the in planta substrate and product, respectively. These data demonstrate that in-chain hydroxy lauric acids are essential building blocks in sporopollenin synthesis and enable the formation of ester and ether linkages with phenylpropanoid units. This study identifies CYP703 as a P450 family specifically involved in pollen development.

This article has been cited by other articles:

				C. de Azevedo Souza, S. S. Kim, S. Koch, L. Kienow, K. Schneider, S. M. McKim, G. W. Haughn, E. Kombrink, and C. J. Douglas A Novel Fatty Acyl-CoA Synthetase Is Required for Pollen Development and Sporopollenin Biosynthesis in Arabidopsis PLANT CELL, February 1, 2009; 21(2): 507 - 525. [Abstract] [Full Text] [PDF]

				M.-D. Huang, F.-J. Wei, C.-C. Wu, Y.-I. C. Hsing, and A. H.C. Huang Analyses of Advanced Rice Anther Transcriptomes Reveal Global Tapetum Secretory Functions and Potential Proteins for Lipid Exine Formation Plant Physiology, February 1, 2009; 149(2): 694 - 707. [Abstract] [Full Text] [PDF]

				T. Suzuki, K. Masaoka, M. Nishi, K. Nakamura, and S. Ishiguro Identification of kaonashi Mutants Showing Abnormal Pollen Exine Structure in Arabidopsis thaliana Plant Cell Physiol., October 1, 2008; 49(10): 1465 - 1477. [Abstract] [Full Text] [PDF]

				D.-S. Zhang, W.-Q. Liang, Z. Yuan, N. Li, J. Shi, J. Wang, Y.-M. Liu, W.-J. Yu, and D.-B. Zhang Tapetum Degeneration Retardation is Critical for Aliphatic Metabolism and Gene Regulation during Rice Pollen Development Mol Plant, July 1, 2008; 1(4): 599 - 610. [Abstract] [Full Text] [PDF]

				T. Ariizumi, T. Kawanabe, K. Hatakeyama, S. Sato, T. Kato, S. Tabata, and K. Toriyama Ultrastructural Characterization of Exine Development of the transient defective exine 1 Mutant Suggests the Existence of a Factor Involved in Constructing Reticulate Exine Architecture from Sporopollenin Aggregates Plant Cell Physiol., January 1, 2008; 49(1): 58 - 67. [Abstract] [Full Text] [PDF]

				S. Greer, M. Wen, D. Bird, X. Wu, L. Samuels, L. Kunst, and R. Jetter The Cytochrome P450 Enzyme CYP96A15 Is the Midchain Alkane Hydroxylase Responsible for Formation of Secondary Alcohols and Ketones in Stem Cuticular Wax of Arabidopsis Plant Physiology, November 1, 2007; 145(3): 653 - 667. [Abstract] [Full Text] [PDF]