Biosynthesis of cembratrienols in cell-free extracts from trichomes of Nicotiana tabacum

Guo, Zhenhua; Wagner, George J.

doi:10.1016/0168-9452(95)04174-s

Cited by 42 publications

(26 citation statements)

References 14 publications

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“…However, most diterpenoids are cyclic, and there appear to be two major, and fundamentally different, modes of cyclization in this class. The macrocyclic diterpenes, such as casbene (38), cembrene (39), and taxadiene (40,41), are formed by cyclizations analogous to those of the monoterpene and sesquiterpene series (Fig. 4).…”

Section: Enzymology and Mechanism Of Terpenoid Cyclizationmentioning

confidence: 99%

Plant terpenoid synthases: Molecular biology and phylogenetic analysis

Bohlmann

Meyer-Gauen

Croteau

1998

Proc. Natl. Acad. Sci. U.S.A.

976

840

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This review focuses on the monoterpene, sesquiterpene, and diterpene synthases of plant origin that use the corresponding C 10 , C 15 , and C 20 prenyl diphosphates as substrates to generate the enormous diversity of carbon skeletons characteristic of the terpenoid family of natural products. A description of the enzymology and mechanism of terpenoid cyclization is followed by a discussion of molecular cloning and heterologous expression of terpenoid synthases. Sequence relatedness and phylogenetic reconstruction, based on 33 members of the Tps gene family, are delineated, and comparison of important structural features of these enzymes is provided. The review concludes with an overview of the organization and regulation of terpenoid metabolism, and of the biotechnological applications of terpenoid synthase genes.The pathways of monoterpene, sesquiterpene, and diterpene biosynthesis are conveniently divided into several stages. The first encompasses the synthesis of isopentenyl diphosphate, isomerization to dimethylallyl diphosphate, prenyltransferase-catalyzed condensation of these two C 5 -units to geranyl diphosphate (GDP), and the subsequent 1Ј-4 additions of isopentenyl diphosphate to generate farnesyl (FDP) and geranylgeranyl (GGDP) diphosphate ( Fig. 1) (1). In the second stage, the prenyl diphosphates undergo a range of cyclizations based on variations on the same mechanistic theme to produce the parent skeletons of each class. Thus, GDP (C 10 ) gives rise to monoterpenes (2), FDP (C 15 ) to sesquiterpenes (3), and GGDP (C 20 ) to diterpenes (4). These transformations catalyzed by the terpenoid synthases (cyclases) may be followed by a variety of redox modifications of the parent skeletal types to produce the many thousands of different terpenoid metabolites of the essential oils, turpentines, and resins of plant origin (5).This review focuses on the synthases that use prenyl diphosphate substrates to generate the enormous diversity of carbon skeletons characteristic of terpenoids. Most of these natural products are cyclic, and many contain multiple ring systems, the basic structures of which are determined by the highly specific terpenoid synthases; examples of synthases that produce acyclic products are also known. The terpenoid synthases may be involved in the regulation of pathway flux because they operate at metabolic branch points and catalyze the first committed steps leading to the various terpene classes (6). The synthases responsible for generating the parent compounds of the various types are quite similar in properties (7), and all operate by electrophilic reaction mechanisms, as do the prenyltransferases (8, 9). Comprehensive treatment of the topic, especially enzymological and mechanistic aspects, has been provided recently (2-4), and the field is periodically surveyed (10, 11). After brief coverage of the three types of terpene synthases from higher plants, with emphasis on common features of structure and function, we focus here on molecular cloning and sequence analysis of these ...

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Section: Enzymology and Mechanism Of Terpenoid Cyclizationmentioning

confidence: 99%

Plant terpenoid synthases: Molecular biology and phylogenetic analysis

Bohlmann

Meyer-Gauen

Croteau

1998

Proc. Natl. Acad. Sci. U.S.A.

976

840

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“…HGL-DTGs are not found on the surface or in the trichomes of N. attenuata leaves (Roda et al, 2003), although other diterpenoids have been found in trichomes of N. tabacum (Lin and Wagner, 1994;Guo and Wagner, 1995). Concentrations of particular HGL-DTGs vary seasonally in flowers of L. chinense (Terauchi et al, 1997b).…”

Section: Introductionmentioning

confidence: 99%

Jasmonate and ppHsystemin Regulate Key Malonylation Steps in the Biosynthesis of 17-Hydroxygeranyllinalool Diterpene Glycosides, an Abundant and Effective Direct Defense against Herbivores inNicotiana attenuata

et al. 2010

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We identified 11 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) that occur in concentrations equivalent to starch (mg/g fresh mass) in aboveground tissues of coyote tobacco (Nicotiana attenuata) and differ in their sugar moieties and malonyl sugar esters (0-2). Concentrations of HGL-DTGs, particularly malonylated compounds, are highest in young and reproductive tissues. Within a tissue, herbivore elicitation changes concentrations and biosynthetic kinetics of individual compounds. Using stably transformed N. attenuata plants silenced in jasmonate production and perception, or production of N. attenuata Hyp-rich glycopeptide systemin precursor by RNA interference, we identified malonylation as the key biosynthetic step regulated by herbivory and jasmonate signaling. We stably silenced N. attenuata geranylgeranyl diphosphate synthase (ggpps) to reduce precursors for the HGL-DTG skeleton, resulting in reduced total HGL-DTGs and greater vulnerability to native herbivores in the field. Larvae of the specialist tobacco hornworm (Manduca sexta) grew up to 10 times as large on ggpps silenced plants, and silenced plants suffered significantly more damage from herbivores in N. attenuata's native habitat than did wild-type plants. We propose that high concentrations of HGL-DTGs effectively defend valuable tissues against herbivores and that malonylation may play an important role in regulating the distribution and storage of HGL-DTGs in plants.

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“…Among these metabolites, Suc esters are predominant and highly toxic to whiteflies (Bemisia tabaci; Severson et al, 1984;Lin and Wagner, 1994). Cembrenoid diterpene has neurotoxic, cytotoxic, and antimitotic activities (Guo and Wagner, 1995).…”

mentioning

confidence: 99%

Release of Hormones from Conjugates: Chloroplast Expression of β-Glucosidase Results in Elevated Phytohormone Levels Associated with Significant Increase in Biomass and Protection from Aphids or Whiteflies Conferred by Sucrose Esters

et al. 2010

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Transplastomic tobacco (Nicotiana tabacum) plants expressing b-glucosidase (Bgl-1) show modified development. They flower 1 month earlier with an increase in biomass (1.9-fold), height (1.5-fold), and leaf area (1.6-fold) than untransformed plants. Trichome density on the upper and lower leaf surfaces of BGL-1 plants increase by 10-and 7-fold, respectively, harboring 5-fold more glandular trichomes (as determined by rhodamine B staining), suggesting that BGL-1 lines produce more sugar esters than control plants. Gibberellin (GA) levels were investigated because it is a known regulator of flowering time, plant height, and trichome development. Both GA 1 and GA 4 levels are 2-fold higher in BGL-1 leaves than in untransformed plants but do not increase in other organs. In addition, elevated levels of other plant hormones, including zeatin and indole-3-acetic acid, are observed in BGL-1 lines. Protoplasts from BGL-1 lines divide and form calli without exogenous hormones. Cell division in protoplasts is enhanced 7-fold in the presence of exogenously applied zeatin-O-glucoside conjugate, indicating the release of active hormones from their conjugates. Whitefly (Bemisia tabaci) and aphid (Myzus persicae) populations in control plants are 18 and 15 times higher than in transplastomic lines, respectively. Lethal dose to kill 50% of the test population values of 26.3 and 39.2 mg per whitefly and 23.1 and 35.2 mg per aphid for BGL-1 and untransformed control exudates, respectively, confirm the enhanced toxicity of transplastomic exudates. These data indicate that increase in sugar ester levels in BGL-1 lines might function as an effective biopesticide. This study provides a novel strategy for designing plants for enhanced biomass production and insect control by releasing plant hormones or sugar esters from their conjugates stored within their chloroplasts.

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Biosynthesis of cembratrienols in cell-free extracts from trichomes of Nicotiana tabacum

Cited by 42 publications

References 14 publications

Plant terpenoid synthases: Molecular biology and phylogenetic analysis

Plant terpenoid synthases: Molecular biology and phylogenetic analysis

Jasmonate and ppHsystemin Regulate Key Malonylation Steps in the Biosynthesis of 17-Hydroxygeranyllinalool Diterpene Glycosides, an Abundant and Effective Direct Defense against Herbivores inNicotiana attenuata

Release of Hormones from Conjugates: Chloroplast Expression of β-Glucosidase Results in Elevated Phytohormone Levels Associated with Significant Increase in Biomass and Protection from Aphids or Whiteflies Conferred by Sucrose Esters

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