Proceedings of the Korean Society of Plant Biotechnology Conference (한국식물생명공학회:학술대회논문집)
- 2002.04b
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- Pages.69-75
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- 2002
Metabolic Engineering of the Brassinosteroid Biosynthetic Pathways
Brassinosteroid의 대사공학
- Lee, Mi-Ock (School of Biological Sciences, College of Natural Sciences, Seoul National University) ;
- Song, Ki-Hong (School of Biological Sciences, College of Natural Sciences, Seoul National University) ;
- Lee, Hyun-Kyung (School of Biological Sciences, College of Natural Sciences, Seoul National University) ;
- Jung, Ji-Yoon (School of Biological Sciences, College of Natural Sciences, Seoul National University) ;
- Choe, Vit-Nary (School of Biological Sciences, College of Natural Sciences, Seoul National University) ;
- Choe, Sung-Hwa (School of Biological Sciences, College of Natural Sciences, Seoul National University)
- 이미옥 (서울대학교 자연과학대학 생명과학부) ;
- 송기홍 (서울대학교 자연과학대학 생명과학부) ;
- 이현경 (서울대학교 자연과학대학 생명과학부) ;
- 정지윤 (서울대학교 자연과학대학 생명과학부) ;
- 최빛나리 (서울대학교 자연과학대학 생명과학부) ;
- 최성화 (서울대학교 자연과학대학 생명과학부)
- Published : 2002.04.26
Abstract
Sterols play two major roles in plants: a bulk component in biological membranes and precursors of plant steroid hormones. Physiological effects of plant steroids, brassinosteroids (BRs), include cell elongation, cell division, stress tolerance, and senescence acceleration. Arabidopsis mutants that carry genetic defects in BR biosynthesis or its signaling display characteristic phenotypes, such as short robust inflorescences, dark-green round leaves, and sterility. Currently there are more than 100 dwarf mutants representing 7 genetic loci in Arabidopsis. Mutants of 6 loci, dwf1/dim1/cbb1, cpd/dwf3, dwf4, dwf5, det2/dwf6, dwf7 are rescued by exogenous application of BRs, whereas bri1/dwf2 shares phenotypes with the above 6 loci but are resistant to BRs. These suggest that the 6 loci are defective in BR biosynthesis, and the one locus is in BR signaling. Biochemical analyses, such as intermediate feeding tests, examining the levels of endogenous BR, and molecular cloning of the genes revealed that dwf7, dwf5, and dwf1 are defective in the three consecutive steps of sterol biosynthesis, from episterol to campesterol via 5-dehydroepisterol. Similarly, det2/dwf6, dwf4, and cpd/dwf3 were Shown to be blocked in