Roots and shoots of tomato produce 6-deoxo-28-norcathasterone, 6-deoxo-28-nortyphasterol and 6-deoxo-28-norcastasterone, possible precursors of 28-norcastasterone

Yokota, Takao; Sato, Tatsuro; Takeuchi, Yoshinori; Nomura, T.; Uno, Koyuru; Watanabe, Tsuyoshi; Takatsuto, Suguru

doi:10.1016/s0031-9422(01)00237-0

Cited by 59 publications

(21 citation statements)

References 15 publications

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“…Preparation of recombinant baculovirus DNA containing each cDNA and transfection of Sf9 (Spodoptera furugiperda 9) cells were carried out according to the manufacturer's instructions (Invitrogen, Carlsbad, CA). To express the recombinant P450 proteins, Sf9 cells were propagated as suspension cultures in Grace medium containing 200 mM 5-aminolevulinic acid, 200 mM ferrous citrate, and 0.1% (v/v) Pluronic F-68 (Life Technologies), and incubated in a rotary shaker at 27 C at 150 rpm. Each microsomal fraction of CYP724B2 or CYP90B3 was obtained from infected cells (300 ml of suspension-cultured cells).…”

Section: Methodsmentioning

confidence: 99%

“…In support of this, 28-norcastasterone and putative C 27 BR intermediates such as 6-deoxo-28-norcathasterone, 6-deoxo-28-nortyphasterol, and 6-deoxo-28-norcastasterone were detected in tomato. 27) Kim et al 28) recently found that 28-norcastasterone is a bioactive BR itself and an important precursor of more bioactive BRs such as CS and BL. But any enzymatic function involved in C 27 biosynthesis remains unclear.…”

Section: Early C-22 Hydroxylation Of Brsmentioning

confidence: 99%

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CYP724B2 and CYP90B3 Function in the Early C-22 Hydroxylation Steps of Brassinosteroid Biosynthetic Pathway in Tomato

Ohnishi

Watanabe

Sakata

et al. 2006

Bioscience, Biotechnology, and Biochemistry

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Section: Methodsmentioning

confidence: 99%

Section: Early C-22 Hydroxylation Of Brsmentioning

confidence: 99%

CYP724B2 and CYP90B3 Function in the Early C-22 Hydroxylation Steps of Brassinosteroid Biosynthetic Pathway in Tomato

Ohnishi

Watanabe

Sakata

et al. 2006

Bioscience, Biotechnology, and Biochemistry

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“…6A, blue triangle), because some of the samples had values below detection and therefore, were considered noise (less than 0.1 pg mg 21 of tissue). Both 28-norCS and CS are synthesized from their corresponding higher order precursors (cholesterol and campesterol, respectively) through mutual BR biosynthesis enzymes CONSTITUTIVE PHOTOMORPHOGENIC DWARF (CPD), DWF4, and BRASSINOSTEROID-6-OXIDASE2 (Yokota et al, 2001;Joo et al, 2012). The relative expression levels of these genes in wild-type shoot and roots (Fig.…”

Section: Pi Deprivation Reduces the Accumulation Of Specific Brsmentioning

confidence: 99%

Activity of the Brassinosteroid Transcription Factors BRASSINAZOLE RESISTANT1 and BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1/BRASSINAZOLE RESISTANT2 Blocks Developmental Reprogramming in Response to Low Phosphate Availability

et al. 2014

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Plants feature remarkable developmental plasticity, enabling them to respond to and cope with environmental cues, such as limited availability of phosphate, an essential macronutrient for all organisms. Under this condition, Arabidopsis (Arabidopsis thaliana) roots undergo striking morphological changes, including exhaustion of the primary meristem, impaired unidirectional cell expansion, and elevated density of lateral roots, resulting in shallow root architecture. Here, we show that the activity of two homologous brassinosteroid (BR) transcriptional effectors, BRASSINAZOLE RESISTANT1 (BZR1) and BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1 (BES1)/BZR2, blocks these responses, consequently maintaining normal root development under low phosphate conditions without impacting phosphate homeostasis. We show that phosphate deprivation shifts the intracellular localization of BES1/BZR2 to yield a lower nucleus-to-cytoplasm ratio, whereas replenishing the phosphate supply reverses this ratio within hours. Phosphate deprivation reduces the expression levels of BR biosynthesis genes and the accumulation of the bioactive BR 28-norcastasterone. In agreement, low and high BR levels sensitize and desensitize root response to this adverse condition, respectively. Hence, we propose that the environmentally controlled developmental switch from deep to shallow root architecture involves reductions in BZR1 and BES1/BZR2 levels in the nucleus, which likely play key roles in plant adaptation to phosphate-deficient environments.

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“…Recently, the presence of brassinosteroids (BRs) was demonstrated in Arabidopsis, maize (Zea mays), pea (Pisum sativum), and tomato (Lycopersicon esculentum) roots (Kim et al, 2000;Yokota et al, 2001;Bancos et al, 2002;Shimada et al, 2003). In general, the levels of BRs such as castasterone in roots are clearly below the concentrations in shoots, and roots appear to require active BRs to a much lesser extent than shoots.…”

mentioning

confidence: 99%

Brassinosteroids Promote Root Growth in Arabidopsis

2003

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Although brassinosteroids (BRs) are known to regulate shoot growth, their role in the regulation of root growth is less clear. We show that low concentrations of BRs such as 24-epicastasterone and 24-epibrassinolide promote root elongation in Arabidopsis wild-type plants up to 50% and in BR-deficient mutants such as dwf1-6 (cbb1) and cbb3 (which is allelic to cpd) up to 150%. The growth-stimulating effect of exogenous BRs is not reduced by the auxin transport inhibitor 2,3,5-triidobenzoic acid. BR-deficient mutants show normal gravitropism, and 2,3,5-triidobenzoic acid or higher concentrations of 2,4-dichlorophenoxyacetic acid and naphtaleneacetic acid inhibit root growth in the mutants to the same extent as in wild-type plants. Simultaneous administration of 24-epibrassinolide and 2,4-dichlorophenoxyacetic acid results in largely additive effects. Exogenous gibberellins do not promote root elongation in the BR-deficient mutants, and the sensitivity to the ethylene precursor 1-aminocyclopropane-1-carboxylic acid is not altered. Thus, the root growth-stimulating effect of BRs appears to be largely independent of auxin and gibberellin action. Furthermore, we analyzed BR interactions with other phytohormones on the gene expression level. Only a limited set of auxin-and ethylene-related genes showed altered expression levels. Genes related to other phytohormones barely showed changes, providing further evidence for an autonomous stimulatory effect of BR on root growth.Recently, the presence of brassinosteroids (BRs) was demonstrated in Arabidopsis, maize (Zea mays), pea (Pisum sativum), and tomato (Lycopersicon esculentum) roots (Kim et al., 2000;Yokota et al., 2001; Bancos et al., 2002;Shimada et al., 2003). In general, the levels of BRs such as castasterone in roots are clearly below the concentrations in shoots, and roots appear to require active BRs to a much lesser extent than shoots. In agreement with the detection of BRs in roots, genes involved in BR biosynthesis (Bancos et al., 2002) and genes involved in BR signaling (Friedrichsen et al., 2000) are expressed in roots. These findings suggest that BRs are important regulatory substances in roots.Previous studies merely analyzed the effects of exogenously supplied BRs on root growth. To this end, different systems such as shoot cuttings (analysis of adventitious root formation), cultured excised roots, root segments, and seedling roots (Roddick and Guan, 1991) were used. In general, BRs inhibit adventitious root formation even though root induction has also been reported occasionally (e.g. Sathiyamoorthy and Nakamura, 1990). Root cuttings were used widely to analyze BR effects on main root elongation and lateral root formation. This system can provide valuable hints in determining whether roots respond directly to BRs or indirectly via primary effects on the shoot. Both inhibitory effects (e.g. Guan and Roddick, 1988;Roddick et al., 1993) and stimulating effects (e.g. Romani et al., 1983) were observed. However, potential cross talk with other phytohormone...

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Roots and shoots of tomato produce 6-deoxo-28-norcathasterone, 6-deoxo-28-nortyphasterol and 6-deoxo-28-norcastasterone, possible precursors of 28-norcastasterone

Cited by 59 publications

References 15 publications

CYP724B2 and CYP90B3 Function in the Early C-22 Hydroxylation Steps of Brassinosteroid Biosynthetic Pathway in Tomato

CYP724B2 and CYP90B3 Function in the Early C-22 Hydroxylation Steps of Brassinosteroid Biosynthetic Pathway in Tomato

Activity of the Brassinosteroid Transcription Factors BRASSINAZOLE RESISTANT1 and BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1/BRASSINAZOLE RESISTANT2 Blocks Developmental Reprogramming in Response to Low Phosphate Availability

Brassinosteroids Promote Root Growth in Arabidopsis

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