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A mutation in Arabidopsis cytochrome b5 reductase identified by high-throughput screening differentially affects hydroxylation and desaturation.
Plant J. 2006 Dec; 48(6):920-32.PJ

Abstract

As a model for analyzing the production of novel fatty acids in oilseeds, we used the genetic and molecular techniques available for Arabidopsis to characterize modifying mutations affecting the accumulation of hydroxy fatty acids in the seeds of Arabidopsis plants that express a transgene for the castor bean fatty acid hydroxylase, FAH12. We developed a high-throughput analytical system and used it to identify three complementation classes of mutations with reduced hydroxy fatty acid accumulation from among Arabidopsis M3 seed samples derived from chemical mutagenesis. We identified one of the mutations by positional cloning as a single base pair change in a gene encoding NADH:cytochrome b5 reductase (CBR1, At5g17770). When expressed in yeast, the mutant form of the enzyme was less active and less stable than the wild-type enzyme. Characterization of homozygous mutant lines with and without the FAH12 transgene (FAH12 cbr1-1 and cbr1-1, respectively) indicated that the only detectable consequence of the cbr1-1 mutation was on desaturase and hydroxylase reactions in the developing seed. The leaf and root fatty compositions, as well as the growth, development and seed production of mutant plants were indistinguishable from wild type. Interestingly, while the cbr1-1 mutation reduced the accumulation of hydroxy fatty acids in seeds by 85%, the effects on 18:1 and 18:2 desaturation reactions were much less (<25% and <60%, respectively). These results suggest that there is competition in developing seeds among the several reactions that utilize reduced cytochrome b5.

Authors+Show Affiliations

Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

17227547

Citation

Kumar, Rajesh, et al. "A Mutation in Arabidopsis Cytochrome B5 Reductase Identified By High-throughput Screening Differentially Affects Hydroxylation and Desaturation." The Plant Journal : for Cell and Molecular Biology, vol. 48, no. 6, 2006, pp. 920-32.
Kumar R, Wallis JG, Skidmore C, et al. A mutation in Arabidopsis cytochrome b5 reductase identified by high-throughput screening differentially affects hydroxylation and desaturation. Plant J. 2006;48(6):920-32.
Kumar, R., Wallis, J. G., Skidmore, C., & Browse, J. (2006). A mutation in Arabidopsis cytochrome b5 reductase identified by high-throughput screening differentially affects hydroxylation and desaturation. The Plant Journal : for Cell and Molecular Biology, 48(6), 920-32.
Kumar R, et al. A Mutation in Arabidopsis Cytochrome B5 Reductase Identified By High-throughput Screening Differentially Affects Hydroxylation and Desaturation. Plant J. 2006;48(6):920-32. PubMed PMID: 17227547.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - A mutation in Arabidopsis cytochrome b5 reductase identified by high-throughput screening differentially affects hydroxylation and desaturation. AU - Kumar,Rajesh, AU - Wallis,James G, AU - Skidmore,Chris, AU - Browse,John, PY - 2007/1/18/pubmed PY - 2007/4/18/medline PY - 2007/1/18/entrez SP - 920 EP - 32 JF - The Plant journal : for cell and molecular biology JO - Plant J VL - 48 IS - 6 N2 - As a model for analyzing the production of novel fatty acids in oilseeds, we used the genetic and molecular techniques available for Arabidopsis to characterize modifying mutations affecting the accumulation of hydroxy fatty acids in the seeds of Arabidopsis plants that express a transgene for the castor bean fatty acid hydroxylase, FAH12. We developed a high-throughput analytical system and used it to identify three complementation classes of mutations with reduced hydroxy fatty acid accumulation from among Arabidopsis M3 seed samples derived from chemical mutagenesis. We identified one of the mutations by positional cloning as a single base pair change in a gene encoding NADH:cytochrome b5 reductase (CBR1, At5g17770). When expressed in yeast, the mutant form of the enzyme was less active and less stable than the wild-type enzyme. Characterization of homozygous mutant lines with and without the FAH12 transgene (FAH12 cbr1-1 and cbr1-1, respectively) indicated that the only detectable consequence of the cbr1-1 mutation was on desaturase and hydroxylase reactions in the developing seed. The leaf and root fatty compositions, as well as the growth, development and seed production of mutant plants were indistinguishable from wild type. Interestingly, while the cbr1-1 mutation reduced the accumulation of hydroxy fatty acids in seeds by 85%, the effects on 18:1 and 18:2 desaturation reactions were much less (<25% and <60%, respectively). These results suggest that there is competition in developing seeds among the several reactions that utilize reduced cytochrome b5. SN - 0960-7412 UR - https://www.unboundmedicine.com/medline/citation/17227547/A_mutation_in_Arabidopsis_cytochrome_b5_reductase_identified_by_high_throughput_screening_differentially_affects_hydroxylation_and_desaturation_ L2 - https://doi.org/10.1111/j.1365-313X.2006.02925.x DB - PRIME DP - Unbound Medicine ER -