Novel biosynthetic pathway of castasterone from cholesterol in tomato
DC Field | Value | Language |
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dc.contributor.author | Kim, Tae-Wuk | - |
dc.contributor.author | Chang, Soo Chul | - |
dc.contributor.author | Lee, June Seung | - |
dc.contributor.author | Takatsuto, Suguru | - |
dc.contributor.author | Yokota, Takao | - |
dc.contributor.author | Kim, Seong-Ki | - |
dc.date.available | 2019-05-30T08:36:49Z | - |
dc.date.issued | 2004-07 | - |
dc.identifier.issn | 0032-0889 | - |
dc.identifier.issn | 1532-2548 | - |
dc.identifier.uri | https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/24816 | - |
dc.description.abstract | Endogenous brassinosteroids (BRs) in tomato (Lycopersicon esculentum) seedlings are known to be composed of C-27- and C-28-BRs. The biosynthetic pathways of C-27-BRs were examined using a cell-free enzyme solution prepared from tomato seedlings that yielded the biosynthetic sequences cholesterol --> cholestanol and 6-deoxo-28-norteasterone <----> 6-deoxo-28-nor-3-dehydroteasterone <----> 6-deoxo-28-nortyphasterol --> 6-deoxo-28-norcastasterone --> 28-norcastasterone (28-norCS). Arabidopsis CYP85A1 that was heterologously expressed in yeast mediated the conversion of 6-deoxo-28-norCS to 28-norCS. The same reaction was catalyzed by an enzyme solution from wild-type tomato but not by an extract derived from a tomato dwarf mutant with a defect in CYP85. Furthermore, exogenously applied 28-norCS restored the abnormal growth of the dwarf mutant. These findings indicate that the C-6 oxidation of 6-deoxo-28-norCS to 28-norCS in tomato seedlings is catalyzed by CYP85, just as in the conversion of 6-deoxoCS to CS. Additionally, the cell-free solution also catalyzed the C-24 methylation of 28-norCS to CS in the presence of NADPH and S-adenosylmethionine (SAM), a reaction that was clearly retarded in the absence of NADPH and SAM. Thus it seems that C-27-BRs, in addition to C-28-BRs, are important in the production of more active C-28-BRs and CS, where a SAM-dependent sterol methyltransferase appears to biosynthetically connect C27-BRs to C28-BRs. Moreover, the tomato cell-free solution converted CS to 26-norCS and [H-2(6)]CS to [H-2(3)]28-norCS, suggesting that C-28 demethylation is an artifact due to an isotope effect. Although previous feeding experiments employing [H-2(6)]CS suggested that 28-norCS was synthesized from CS in certain plant species, this is not supported in planta. Altogether, this study demonstrated for the first time, to our knowledge, that 28-norCS is not synthesized from CS but from cholesterol. In addition, CS and [H-2(6)]CS were not ;converted into BL and [H-2(6)]BL, respectively, confirming an earlier finding that the active BR in tomato seedlings is not BL but CS. In conclusion, the biosynthesis of 28-norBRs appears to play a physiologically important role in maintaining homeostatic levels of CS in tomato seedlings. | - |
dc.format.extent | 12 | - |
dc.language | 영어 | - |
dc.language.iso | ENG | - |
dc.publisher | AMER SOC PLANT BIOLOGISTS | - |
dc.title | Novel biosynthetic pathway of castasterone from cholesterol in tomato | - |
dc.type | Article | - |
dc.identifier.doi | 10.1104/pp.104.043588 | - |
dc.identifier.bibliographicCitation | PLANT PHYSIOLOGY, v.135, no.3, pp 1231 - 1242 | - |
dc.description.isOpenAccess | N | - |
dc.identifier.wosid | 000222692700009 | - |
dc.identifier.scopusid | 2-s2.0-3543019726 | - |
dc.citation.endPage | 1242 | - |
dc.citation.number | 3 | - |
dc.citation.startPage | 1231 | - |
dc.citation.title | PLANT PHYSIOLOGY | - |
dc.citation.volume | 135 | - |
dc.type.docType | Article | - |
dc.publisher.location | 미국 | - |
dc.subject.keywordPlus | BRASSINOSTEROID BIOSYNTHESIS | - |
dc.subject.keywordPlus | MARCHANTIA-POLYMORPHA | - |
dc.subject.keywordPlus | PHASEOLUS-VULGARIS | - |
dc.subject.keywordPlus | CULTURED-CELLS | - |
dc.subject.keywordPlus | SIGNAL-TRANSDUCTION | - |
dc.subject.keywordPlus | CATHARANTHUS-ROSEUS | - |
dc.subject.keywordPlus | YEAST EXPRESSION | - |
dc.subject.keywordPlus | C-6 OXIDATION | - |
dc.subject.keywordPlus | PLANT-GROWTH | - |
dc.subject.keywordPlus | ARABIDOPSIS | - |
dc.relation.journalResearchArea | Plant Sciences | - |
dc.relation.journalWebOfScienceCategory | Plant Sciences | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
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