Enzymology and compartmentation of polymethylated flavonol glucosides in chrysosplenium americanum

Ibrahim, Ragai K.; Luca, Vincenzo De; Khouri, Henry E.; Latchinian, Lilian; Brisson, Louise F.; Charest, Pascale G.

doi:10.1016/s0031-9422(00)81789-6

Cited by 93 publications

(68 citation statements)

References 45 publications

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“…They consist mostly of mono-to tetrasulfate esters of common hydroxyflavones and hydroxyflavonols. Whereas the enzymic O-methylation (15,18) and O-glucosylation (14,16) of flavonoids have been extensively studied, little is known of their enzymic sulfation in plants. In contrast,e there have been extensive studies of the enzymic sulfation of endogenous metabolites and xenobiotics in animal tissues, which led to the purification of several classes of sulfotransferases (13,17,19 …”

Section: Plant Materialsmentioning

confidence: 99%

Partial Purification and Characterization of Three Flavonol-Specific Sulfotransferases from Flaveria chloraefolia

Varin¹,

Ibrahim²

1989

Plant Physiol.

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Three distinct flavonol-specific sulfotransferases were partially purified from the shoot tips of Flaveria chloraefolia A. Gray by fractional precipitation with ammonium sulfate, followed by gel filtration on Sephacryl S-200, 3'-phosphoadenosine 5-phosphateAgarose affinity chromatography and chromatofocusing on Mono P. These enzymes exhibited expressed specificity for positions 3 of various flavonol acceptors and of 3' and 4' of flavonol 3-sulfate. The three sulfotransferases had similar molecular weights (35,000), exhibited no requirement for divalent cations and were not inhibited by SH group reagents. Their Km values for both the sulfate donor and the flavonol acceptors were of the same order of magnitude (ca. 0.2-0.4 micromolar). Except for the 3-sulfotransferase, which exhibited two optima at pH 6.5 and 8.5, the 3' and the 4'-sulfotransferases had a pH optimum of 7.5. The three enzymes could be resolved only by chromatofocusing and were eluted at pH 5.4, pH 6.0, and pH 5.1 for the 3-, 3'-and 4'-sulfotransferases, respectively. The substrate specificity of these three enzymes is discussed in relation to the biosynthesis of polysulfated flavonols in F. chloraefolia. assay for flavonoid ST2 activity. The -).Recent studies (2,9) indicated that Flaveria chloraefolia is a rich source of mono-and disulfate esters of quercetin and patuletin (see Scheme I), with sulfation at positions 3, 3', or 4' on the flavonoid ring (3, 7), as well as several 6-methoxyflavonol 3-monosulfates (8). It was considered of interest, therefore, to study the ST system of this tissue and to determine the sequence of enzymic sulfation of these metabolites.

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Section: Plant Materialsmentioning

confidence: 99%

Partial Purification and Characterization of Three Flavonol-Specific Sulfotransferases from Flaveria chloraefolia

Varin¹,

Ibrahim²

1989

Plant Physiol.

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“…Isoflavonoid secretion affects the surrounding microflora in the rhizosphere (Weisskopf et al, 2006), attracts mutualistic microorganisms such as nitrogen-fixing bacteria, and enhances defense responses to pathogens (Paiva, 2000;Dakora and Phillips, 2002). Flavonol glycosides have been detected in the cell wall fraction of Scots pine (Pinus sylvestris) needles (kaempferol 3-glucoside; Schnitzler et al, 1996) and Chrysosplenium americanum (polymethylated flavonol glucosides; Ibrahim et al, 1987), while flavonoid aglycones, including flavones and flavonols, have been detected in exudates of numerous species (Valant-Vetschera and Wollenweber, 2001;Wollenweber et al, 2003).…”

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confidence: 99%

Flavonoid Biosynthesis in Barley Primary Leaves Requires the Presence of the Vacuole and Controls the Activity of Vacuolar Flavonoid Transport

et al. 2007

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Barley (Hordeum vulgare) primary leaves synthesize saponarin, a 2-fold glucosylated flavone (apigenin 6-C-glucosyl-7-Oglucoside), which is efficiently accumulated in vacuoles via a transport mechanism driven by the proton gradient. Vacuoles isolated from mesophyll protoplasts of the plant line anthocyanin-less310 (ant310), which contains a mutation in the chalcone isomerase (CHI) gene that largely inhibits flavonoid biosynthesis, exhibit strongly reduced transport activity for saponarin and its precursor isovitexin (apigenin 6-C-glucoside). Incubation of ant310 primary leaf segments or isolated mesophyll protoplasts with naringenin, the product of the CHI reaction, restores saponarin biosynthesis almost completely, up to levels of the wild-type Ca33787. During reconstitution, saponarin accumulates to more than 90% in the vacuole. The capacity to synthesize saponarin from naringenin is strongly reduced in ant310 miniprotoplasts containing no central vacuole. Leaf segments and protoplasts from ant310 treated with naringenin showed strong reactivation of saponarin or isovitexin uptake by vacuoles, while the activity of the UDP-glucose:isovitexin 7-O-glucosyltransferase was not changed by this treatment. Our results demonstrate that efficient vacuolar flavonoid transport is linked to intact flavonoid biosynthesis in barley. Intact flavonoid biosynthesis exerts control over the activity of the vacuolar flavonoid/H 1 -antiporter. Thus, the barley ant310 mutant represents a novel model system to study the interplay between flavonoid biosynthesis and the vacuolar storage mechanism.

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“…The commitment to differentiate into specialized structures involves the perception by cells in the meristem of a complex array of signals, which communicate cellular age, position in relation to other cells, and hormonal balance. Environmental factors, such as light and temperature, also play a critical role in modulating these signals throughout the process of organogenesis (Bernier, 1988;Dale, 1988;Sylvester et al, 1996).In addition to morphogenesis, developmental processes result in biochemical specialization of cells for the biosynthesis and/or accumulation of secondary metabolites, such as phenylpropanoids (Ibrahim et al, 1987;Reinold and Hahlbrock, 1997), monoterpenoids (Fahn, 1988;McCaskill et al, 1992), and alkaloids (Robinson, 1974(Robinson, , 1981Nessler and Mahlberg, 1977;Eilert et al, 1985;Hashimoto and Yamada, 1994;Facchini and De Luca, 1995). Studies with germinating seedlings have suggested that alkaloid biosynthesis and accumulation are associated with seedling development (Weeks and Bush, 1974;De Luca et al, 1986;Aerts et al, 1994).…”

mentioning

confidence: 99%

Multicellular Compartmentation of Catharanthus roseus Alkaloid Biosynthesis Predicts Intercellular Translocation of a Pathway Intermediate

1999

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In situ RNA hybridization and immunocytochemistry were used to establish the cellular distribution of monoterpenoid indole alkaloid biosynthesis in Madagascar periwinkle ( Catharanthus roseus ). Tryptophan decarboxylase (TDC) and strictosidine synthase (STR1), which are involved in the biosynthesis of the central intermediate strictosidine, and desacetoxyvindoline 4-hydroxylase (D4H) and deacetylvindoline 4-O -acetyltransferase (DAT), which are involved in the terminal steps of vindoline biosynthesis, were localized. tdc and str1 mRNAs were present in the epidermis of stems, leaves, and flower buds, whereas they appeared in most protoderm and cortical cells around the apical meristem of root tips. In marked contrast, d4h and dat mRNAs were associated with the laticifer and idioblast cells of leaves, stems, and flower buds. Immunocytochemical localization for TDC, D4H, and DAT proteins confirmed the differential localization of early and late stages of vindoline biosynthesis. Therefore, we concluded that the elaboration of the major leaf alkaloids involves the participation of at least two cell types and requires the intercellular translocation of a pathway intermediate. A basipetal gradient of expression in maturing leaves also was shown for all four genes by in situ RNA hybridization studies and by complementary studies with dissected leaves, suggesting that expression of the vindoline pathway occurs transiently during early leaf development. These results partially explain why attempts to produce vindoline by cell culture technology have failed. INTRODUCTIONThe organs forming the plant body consist of several different cell types that are organized in relation to each other and that confer specific functions to the resulting organ. Each cell type emerges from an undifferentiated meristem according to a sophisticated and partially understood developmental program (Sylvester et al., 1996;von Arnim and Deng, 1996). The commitment to differentiate into specialized structures involves the perception by cells in the meristem of a complex array of signals, which communicate cellular age, position in relation to other cells, and hormonal balance. Environmental factors, such as light and temperature, also play a critical role in modulating these signals throughout the process of organogenesis (Bernier, 1988;Dale, 1988;Sylvester et al., 1996).In addition to morphogenesis, developmental processes result in biochemical specialization of cells for the biosynthesis and/or accumulation of secondary metabolites, such as phenylpropanoids (Ibrahim et al., 1987;Reinold and Hahlbrock, 1997), monoterpenoids (Fahn, 1988;McCaskill et al., 1992), and alkaloids (Robinson, 1974(Robinson, , 1981Nessler and Mahlberg, 1977;Eilert et al., 1985;Hashimoto and Yamada, 1994;Facchini and De Luca, 1995). Studies with germinating seedlings have suggested that alkaloid biosynthesis and accumulation are associated with seedling development (Weeks and Bush, 1974;De Luca et al., 1986;Aerts et al., 1994). Studies with mature plants also reveal this ty...

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Enzymology and compartmentation of polymethylated flavonol glucosides in chrysosplenium americanum

Cited by 93 publications

References 45 publications

Partial Purification and Characterization of Three Flavonol-Specific Sulfotransferases from Flaveria chloraefolia

Partial Purification and Characterization of Three Flavonol-Specific Sulfotransferases from Flaveria chloraefolia

Flavonoid Biosynthesis in Barley Primary Leaves Requires the Presence of the Vacuole and Controls the Activity of Vacuolar Flavonoid Transport

Multicellular Compartmentation of Catharanthus roseus Alkaloid Biosynthesis Predicts Intercellular Translocation of a Pathway Intermediate

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