• 제목/요약/키워드: brassinosteroids

검색결과 79건 처리시간 0.023초

Marchantia polymopha(우산이끼) 현택배양 세포내으 4-methylster이들의 동정 (Identification of 4-Demethylsterols from Suspension Cultured Cells of Marchantia polymorpha L.)

  • Seong-Ki Kim
    • Journal of Plant Biology
    • /
    • 제38권3호
    • /
    • pp.219-225
    • /
    • 1995

  • Five kinds of 4-demethylsterol were isolated from suspension cultured cells of a liverworth, Marchantia polymorpha. Four 4-demethylsterols among them were analyzed by a capillary gas chromatography-massspectrometry and 500 MHz 1H-NMR, and characterized to be avenasterol, 24-methylene-cholesterol, stigmasterol, and campesterol. And the fifth 4-demethylsterol was characterized to be sitosterol by a capillary gas chromatography-mass spectrometry. The concentration of the 4-demethylsterols in the cell decreased in order of avenasterol>stigmasterol>24-methylene-cholesterol>campesterol>sitosterol. When carbon skeleton and the oxidation state was compared with those of brassinosteroids, these 4-demethylsterols may be potent biosynthetic procusors of brassinosteroids in the cells.

  • PDF

Antagonistic Regulation of Arabidopsis Growth by Brassinosteroids and Abiotic Stresses

  • Chung, Yuhee;Kwon, Soon Il;Choe, Sunghwa
    • Molecules and Cells
    • /
    • 제37권11호
    • /
    • pp.795-803
    • /
    • 2014

  • To withstand ever-changing environmental stresses, plants are equipped with phytohormone-mediated stress resistance mechanisms. Salt stress triggers abscisic acid (ABA) signaling, which enhances stress tolerance at the expense of growth. ABA is thought to inhibit the action of growth-promoting hormones, including brassinosteroids (BRs). However, the regulatory mechanisms that coordinate ABA and BR activity remain to be discovered. We noticed that ABA-treated seedlings exhibited small, round leaves and short roots, a phenotype that is characteristic of the BR signaling mutant, brassinosteroid insensitive1-9 (bri1-9). To identify genes that are antagonistically regulated by ABA and BRs, we examined published Arabidopsis microarray data sets. Of the list of genes identified, those upregulated by ABA but downregulated by BRs were enriched with a BRRE motif in their promoter sequences. After validating the microarray data using quantitative RT-PCR, we focused on RD26, which is induced by salt stress. Histochemical analysis of transgenic Arabidopsis plants expressing RD26pro:GUS revealed that the induction of GUS expression after NaCl treatment was suppressed by co-treatment with BRs, but enhanced by co-treatment with propiconazole, a BR biosynthetic inhibitor. Similarly, treatment with bikinin, an inhibitor of BIN2 kinase, not only inhibited RD26 expression, but also reduced the survival rate of the plant following exposure to salt stress. Our results suggest that ABA and BRs act antagonistically on their target genes at or after the BIN2 step in BR signaling pathways, and suggest a mechanism by which plants fine-tune their growth, particularly when stress responses and growth compete for resources.

  • https://doi.org/10.14348/molcells.2014.0127 인용 PDF KSCI