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Mycobacterium tuberculosis (Mtb) has a highly complex cell wall, which is required for both bacterial survival and infection. Cell wall biosynthesis is dependent on decaprenyl diphosphate as a glyco-carrier, which is hence an essential metabolite in this pathogen. Previous biochemical studies indicated (E)-geranyl diphosphate (GPP) is required for the synthesis of decaprenyl diphosphate. Here we demonstrate that Rv0989c encodes the “missing” GPP synthase, representing the first such enzyme to be characterized from bacteria, and which presumably is involved in decaprenyl diphosphate biosynthesis in Mtb. Our investigation also has revealed previously unrecognized substrate plasticity of the farnesyl diphosphate synthases from Mtb, resolving previous discrepancies between biochemical and genetic studies of cell wall biosynthesis. 相似文献
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Identification and functional analysis of two P450 enzymes of Gossypium hirsutum involved in DMNT and TMTT biosynthesis 总被引:2,自引:0,他引:2
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Danfeng Liu Xinzheng Huang Weixia Jing Xingkui An Qiang Zhang Hong Zhang Jingjiang Zhou Yongjun Zhang Yuyuan Guo 《Plant biotechnology journal》2018,16(2):581-590
The homoterpenes (3E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) and (E,E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene (TMTT) are major herbivore‐induced plant volatiles that can attract predatory or parasitic arthropods to protect injured plants from herbivore attack. In this study, DMNT and TMTT were confirmed to be emitted from cotton (Gossypium hirsutum) plants infested with chewing caterpillars or sucking bugs. Two CYP genes (GhCYP82L1 and GhCYP82L2) involved in homoterpene biosynthesis in G. hirsutum were newly identified and characterized. Yeast recombinant expression and enzyme assays indicated that the two GhCYP82Ls are both responsible for the conversion of (E)‐nerolidol to DMNT and (E,E)‐geranyllinalool to TMTT. The two heterologously expressed proteins without cytochrome P450 reductase fail to convert the substrates to homoterpenes. Quantitative real‐time PCR (qPCR) analysis suggested that the two GhCYP82L genes were significantly up‐regulated in leaves and stems of G. hirsutum after herbivore attack. Subsequently, electroantennogram recordings showed that electroantennal responses of Microplitis mediator and Peristenus spretus to DMNT and TMTT were both dose dependent. Laboratory behavioural bioassays showed that females of both wasp species responded positively to DMNT and males and females of M. mediator could be attracted by TMTT. The results provide a better understanding of homoterpene biosynthesis in G. hirsutum and of the potential influence of homoterpenes on the behaviour of natural enemies, which lay a foundation to study genetically modified homoterpene biosynthesis and its possible application in agricultural pest control. 相似文献
5.
Tomato (Lycopersicon esculentum) plants emit a blend of volatile organic compounds, which mainly consists of terpenes. Upon herbivory or wounding, the emission
of several terpenes increases. We have identified and characterized the first two tomato monoterpene synthases, LeMTS1 and
LeMTS2. Although these proteins were highly homologous, recombinant LeMTS1 protein produced (R)-linalool from geranyl diphosphate (GPP) and (E)-nerolidol from farnesyl diphosphate (FPP), while recombinant LeMTS2 produced β-phellandrene, β-myrcene, and sabinene from
GPP. In addition, these genes were expressed in different tissues: LeMTS1 was expressed in flowers, young leaves, stems, and petioles, while LeMTS2 was strongest expressed in stems and roots. LeMTS1 expression in leaves was induced by spider mite-infestation, wounding and jasmonic acid (JA)-treatment, while LeMTS2 did not respond to these stimuli. The expression of LeMTS1 in stems and petioles was predominantly detected in trichomes and could be induced by JA. Because JA treatment strongly induced
emission of linalool and overexpression of LeMTS1 in tomato resulted in increased production of linalool, we propose that LeMTS1 is a genuine linalool synthase. Our results
underline the importance of trichomes in JA-induced terpene emission in tomato. 相似文献
6.
Amorpha-4,11-diene synthase: cloning and functional expression of a key enzyme in the biosynthetic pathway of the novel antimalarial drug artemisinin 总被引:26,自引:0,他引:26
The sesquiterpenoid artemisinin, isolated from the plant Artemisia annua L., and its semi-synthetic derivatives are a new and very effective group of antimalarial drugs. A branch point in the biosynthesis
of this compound is the cyclisation of the ubiquitous precursor farnesyl diphosphate into the first specific precursor of
artemisinin, namely amorpha-4,11-diene. Here we describe the isolation of a cDNA clone encoding amorpha-4,11-diene synthase.
The deduced amino acid sequence exhibits the highest identity (50%) with a putative sesquiterpene cyclase of A. annua. When expressed in Escherichia coli, the recombinant enzyme catalyses the formation of amorpha-4,11-diene from farnesyl diphosphate. Introduction of the gene
into tobacco (Nicotiana tabacum L.) resulted in the expression of an active enzyme and the accumulation of amorpha-4,11-diene ranging from 0.2 to 1.7 ng per g
fresh weight.
Received: 8 June 2000 / Accepted: 21 August 2000 相似文献
7.
Treatment of a Cinchona robusta How. cell suspension culture with a homogenate of Phytophthora cinnamomi resulted in cessation of growth and a rapid induction of the biosynthesis of anthraquinone-type phytoalexins. The strongest
induction of anthraquinone biosynthesis was obtained when the elicitor was added in the early growth phase of the growth cycle.
The accumulation of anthraquinones was accompanied by a tri-phasic response in the activity of isopentenyl diphosphate (IPP)
isomerase (EC 5.3.3.2): phase I was characterised by a rapid induction of activity, reaching a maximum at 12 h after elicitation.
During phase II, IPP isomerase rapidly decreased to levels below those found in untreated cells. At phase III, IPP isomerase
activity increased again, reaching a second maximum at about 72 h after elicitation. During phase I, the activity of farnesyl
diphosphate synthase (EC 2.5.1.10) was found to be suppressed. Extraction and assay conditions were optimised for IPP isomerase.
The presence of Mn2+ in the incubation buffer resulted in a marked increase in the activity of the enzymes obtained from cells in phase I. The
induction of IPP isomerase in combination with a concomitant inhibition of farnesyl diphosphate synthase might result in an
efficient channeling of C5-precursors into phytoalexin biosynthesis.
Received: 23 August 1996 / Accepted: 20 March 1997 相似文献
8.
Holger Danner Sandra Irmisch Feng Chen Sybille B. Unsicker Tobias G. Köllner 《Phytochemistry》2011,72(9):897-908
After herbivore damage, many plants increase their emission of volatile compounds, with terpenes usually comprising the major group of induced volatiles. Populus trichocarpa is the first woody species with a fully sequenced genome, enabling rapid molecular approaches towards characterization of volatile terpene biosynthesis in this and other poplar species. We identified and characterized four terpene synthases (PtTPS1-4) from P. trichocarpa which form major terpene compounds of the volatile blend induced by gypsy moth (Lymantria dispar) feeding. The enzymes were heterologously expressed and assayed with potential prenyl diphosphate substrates. PtTPS1 and PtTPS2 accepted only farnesyl diphosphate and produced (−)-germacrene D and (E,E)-α-farnesene as their major products, respectively. In contrast, PtTPS3 and PtTPS4 showed both mono- and sesquiterpene synthase activity. They produce the acyclic terpene alcohols linalool and nerolidol but exhibited opposite stereospecificity. qRT-PCR analysis revealed that the expression of the respective terpene synthase genes was induced after feeding of gypsy moth caterpillars. The TPS enzyme products may play important roles in indirect defense of poplar to herbivores and in mediating intra- and inter-plant signaling. 相似文献
9.
Summary. Ornithine decarboxylase (ODC) and diamine oxidase (DAO) are important enzymes involved in the metabolism of polyamines (putrescine,
spermidine and spermine). The influence of testosterone (T) and 17, β– estradiol (E2) on the activity of ODC and DAO was examined in cultivated normal rat kidney (NRK) epithelial cells. The results showed an
increase in enzyme activities 4 hours or 12 hours after hormonal treatment. Both T and E2 led to a significant increase (1.6-fold) in ODC protein level as compared to the controls. Cellular concentration of spermidine
and spermine increased (2.2- and 2.6-fold respectively) 4 hours after T addition. A higher levels in concentrations of putrescine
(1.4-fold) and spermine (1.5-fold) 12 hours after E2 treatment were observed. These results suggest that the biosynthesis and terminal oxidation of the polyamines in NRK epithelial
cells are androgen- and estrogen-mediated and depend on the hormonal sensitivity of the cells.
Received April 5, 1999, Accepted December 20, 1999 相似文献
10.
The biochemistry of homoterpenes--common constituents of floral and herbivore-induced plant volatile bouquets 总被引:2,自引:0,他引:2
Volatile organic compounds emitted by plants mediate a variety of interactions between plants and other organisms. The irregular acyclic homoterpenes, 4,8-dimethylnona-1,3,7-triene (DMNT) and 4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT), are among the most widespread volatiles produced by angiosperms with emissions from flowers and from vegetative tissues upon herbivore feeding. Special attention has been placed on the role of homoterpenes in attracting parasitoids and predators of herbivores and has sparked interest in engineering homoterpene formation to improve biological pest control. The biosynthesis of DMNT and TMTT proceeds in two enzymatic steps: the formation of the tertiary C15-, and C20-alcohols, (E)-nerolidol and (E,E)-geranyl linalool, respectively, catalyzed by terpene synthases, and the subsequent oxidative degradation of both alcohols by a single cytochrome P450 monooxygenase (P450). In Arabidopsis thaliana, the herbivore-induced biosynthesis of TMTT is catalyzed by the concerted activities of the (E,E)-geranyllinalool synthase, AtGES, and CYP82G1, a P450 of the so far uncharacterized plant CYP82 family. TMTT formation is in part controlled at the level of AtGES expression. Co-expression of AtGES with CYP82G1 at wound sites allows for an efficient conversion of the alcohol intermediate. The identified homoterpene biosynthesis genes in Arabidopsis and related genes from other plant species provide tools to engineer homoterpene formation and to address questions of the regulation and specific activities of homoterpenes in plant-herbivore interactions. 相似文献
11.
Expression of lima bean terpene synthases in rice enhances recruitment of a beneficial enemy of a major rice pest 总被引:1,自引:0,他引:1
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Fengqi Li Wei Li Yong‐Jun Lin John A. Pickett Michael A. Birkett Kongming Wu Guirong Wang Jing‐Jiang Zhou 《Plant, cell & environment》2018,41(1):111-120
Volatile terpenoids play a key role in plant defence against herbivory by attracting parasitic wasps. We identified seven terpene synthase genes from lima bean, Phaseolus lunatus L. following treatment with either the elicitor alamethicin or spider mites, Tetranychus cinnabarinus. Four of the genes (Pltps2, Pltps3, Pltps4 and Pltps5) were up‐regulated with their derived proteins phylogenetically clustered in the TPS‐g subfamily and PlTPS3 positioned at the base of this cluster. Recombinant PlTPS3 was able to convert geranyl diphosphate and farnesyl diphosphate to linalool and (E)‐nerolidol, the latter being precursor of the homoterpene (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT). Recombinant PlTPS4 showed a different substrate specificity and produced linalool and (E)‐nerolidol, as well as (E,E)‐geranyllinalool from geranylgeranyl diphosphate. Transgenic rice expressing Pltps3 emitted significantly more (S)‐linalool and DMNT than wild‐type plants, whereas transgenic rice expressing Pltps4 produced (S)‐linalool, DMNT and (E,E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene (TMTT). In laboratory bioassays, female Cotesia chilonis, the natural enemy of the striped rice stemborer, Chilo suppressalis, were significantly attracted to the transgenic plants and their volatiles. We further confirmed this with synthetic blends mimicking natural rice volatile composition. Our study demonstrates that the transformation of rice to produce volatile terpenoids has the potential to enhance plant indirect defence through natural enemy recruitment. 相似文献
12.
Yasuyuki Uzuka Takafumi Naganuma Kentaro Tanaka Kiyoshi Suzuki 《Bioscience, biotechnology, and biochemistry》2013,77(3):851-852
In order to investigate the substrate binding feature of undecaprenyl diphosphate synthase from Micrococcus luteus B-P 26 with respect to farnesyl diphosphate and a reaction intermediate, (Z,E,E)-geranylgeranyl diphosphate, we examined the reactivity of artificial substrate analogs, 3-desmethyl farnesyl diphosphate and 3-desmethyl Z-geranylgeranyl diphosphate, which lack the methyl group at the 3-position of farnesyl diphosphate and Z-geranylgeranyl diphosphate, respectively. Undecaprenyl diphosphate synthase did not accept either of the 3-desmethyl analogs as the allylic substrate, indicating that the methyl group at the 3-position of the allylic substrate is important in the undecaprenyl diphosphate synthase reaction. These analogs showed different inhibition patterns in the cis-prenyl chain elongation reaction with respect to the reactions of farnesyl diphosphate and Z-geranylgeranyl diphosphate as allylic substrate. These results suggest that the binding site for the natural substrate farnesyl diphosphate and those for the intermediate allylic diphosphate, which contains the cis-prenyl unit, are different during the cis-prenyl chain elongation reaction. 相似文献
13.
Sucrose synthase (SS), a key enzyme in plant carbohydrate metabolism, has recently been isolated from Anabaena sp. strain PCC 7119, and biochemically characterized; two forms (SS-I and SS-II) were detected (Porchia et al. 1999, Planta
210: 34–40). The present study describes the first isolation and characterization of a prokaryotic SS gene, susA, encoding SS-II from that strain of Anabaena. A 7 kbp DNA fragment containing an open reading frame (EMBL accession number AJ010639) with about 30–40% amino acid identity
with plant SSs was isolated from an Anabaena subgenomic library. The putative SS gene was demonstrated to encode an SS protein by expression in Escherichia coli. The biochemical properties of the recombinant enzyme were identical to those of the enzyme purified from the cyanobacterial
cells. The deduced amino acid sequence of the Anabaena SS diverged from every plant SS reported. The occurrence of SS in cyanobacteria of different taxonomic groups was investigated.
The enzyme occurs in several filamentous nitrogen-fixing cyanobacteria but not in two species of unicellular, non-diazotrophic
cyanobacteria.
Received: 5 January 2000 / Accepted: 7 March 2000 相似文献
14.
James Tabery 《Journal of the history of biology》2008,41(4):717-761
This essay examines the origin(s) of genotype–environment interaction, or G × E. “Origin(s)” and not “the origin” because the thesis is that there were actually two distinct concepts of G × E at this beginning: a
biometric concept, or G × EB, and a developmental concept, or G × ED. R. A. Fisher, one of the founders of population genetics and the creator of the statistical analysis of variance, introduced
the biometric concept as he attempted to resolve one of the main problems in the biometric tradition of biology – partitioning
the relative contributions of nature and nurture responsible for variation in a population. Lancelot Hogben, an experimental
embryologist and also a statistician, introduced the developmental concept as he attempted to resolve one of the main problems
in the developmental tradition of biology – determining the role that developmental relationships between genotype and environment
played in the generation of variation. To argue for this thesis, I outline Fisher and Hogben’s separate routes to their respective
concepts of G × E; then these separate interpretations of G × E are drawn on to explicate a debate between Fisher and Hogben
over the importance of G × E, the first installment of a persistent controversy. Finally, Fisher’s G × EB and Hogben’s G × ED are traced beyond their own work into mid-20th century population and developmental genetics, and then into the infamous
IQ Controversy of the 1970s. 相似文献
15.
Green SA Chen X Nieuwenhuizen NJ Matich AJ Wang MY Bunn BJ Yauk YK Atkinson RG 《Journal of experimental botany》2012,63(5):1951-1967
Flowers of the kiwifruit species Actinidia chinensis produce a mixture of sesquiterpenes derived from farnesyl diphosphate (FDP) and monoterpenes derived from geranyl diphosphate (GDP). The tertiary sesquiterpene alcohol (E)-nerolidol was the major emitted volatile detected by headspace analysis. Contrastingly, in solvent extracts of the flowers, unusually high amounts of (E,E)-farnesol were observed, as well as lesser amounts of (E)-nerolidol, various farnesol and farnesal isomers, and linalool. Using a genomics-based approach, a single gene (AcNES1) was identified in an A. chinensis expressed sequence tag library that had significant homology to known floral terpene synthase enzymes. In vitro characterization of recombinant AcNES1 revealed it was an enzyme that could catalyse the conversion of FDP and GDP to the respective (E)-nerolidol and linalool terpene alcohols. Enantiomeric analysis of both AcNES1 products in vitro and floral terpenes in planta showed that (S)-(E)-nerolidol was the predominant enantiomer. Real-time PCR analysis indicated peak expression of AcNES1 correlated with peak (E)-nerolidol, but not linalool accumulation in flowers. This result, together with subcellular protein localization to the cytoplasm, indicated that AcNES1 was acting as a (S)-(E)-nerolidol synthase in A. chinensis flowers. The synthesis of high (E,E)-farnesol levels appears to compete for the available pool of FDP utilized by AcNES1 for sesquiterpene biosynthesis and hence strongly influences the accumulation and emission of (E)-nerolidol in A. chinensis flowers. 相似文献
16.
Transgenic tobacco (Nicotiana tabacum L.) plants with decreased and increased transport capacities of the chloroplast triose phosphate/phosphate translocator (TPT)
were used to study the control the TPT exerts on the flux of starch and sucrose biosynthesis, as well as CO2 assimilation, respiration and photosynthetic electron transport. For this purpose, tobacco lines with an antisense repression
of the endogenous TPT (αTPT) and tobacco lines overexpressing a TPT gene from Flaveria trinervia (FtTPT) were used. In ambient CO2, there was no or little effect of altered TPT transport activities on either rates of photosynthetic electron transport and/or
CO2 assimilation. However, in elevated CO2 (1500 μl · l−1) and low O2 (2%) the TPT exerted strong control on the rate of CO2 assimilation (control coefficient for the wild type; CJA
TPT=0.30) in saturating light. Similarly, the incorporation of 14C into starch in high CO2 was increased in tobacco plants with decreased TPT activity, but was reduced in plants overexpressing the TPT from F. trinervia. Thus, the TPT exerted negative control on the rate of starch biosynthesis with a CJStarch
TPT=−0.19 in the wild type estimated from a hyperbolic curve fitted to the data points. This was less than the positive control
strength on the rate of sucrose biosynthesis (CJSuc
TPT=0.35 in the wild type). Theoretically, the positive control exerted on sucrose biosynthesis should be numerically identical
to the negative control on starch biosynthesis unless additional metabolic pathways are affected. The rate of dark respiration
showed some correlation with the TPT activity in that it increased in FtTPT overexpressors, but decreased in αTPT plants with
an apparent control coefficient of CJRes
TPT=0.24. If the control on sucrose biosynthesis is referred to as “gain of carbon” (positive control) and the control on starch
biosynthesis as well as dark respiration as a “loss of carbon” (negative control) for sucrose biosynthesis and subsequent
export, the sum of the control coefficients on dark respiration and starch biosynthesis would be numerically similar to the
control coefficient on the rate of sucrose biosynthesis. There was also some control on the rate of photosynthetic electron
transport, but only at high light and in elevated CO2 combined with low O2. The control coefficient for the rate of photosynthetic electron transport was CJETR
TPT=0.16 in the wild type. Control coefficients were also calculated for plants with elevated and lowered TPT activity. Furthermore,
the extent to which starch degradation/glucose utilisation compensates for the lack of triose phosphate export was assessed.
The TPT also exerted control on metabolite contents in air.
Received: 26 March 1999 / Accepted: 21 August 1999 相似文献
17.
12-Oxophytodienoate reductase 3 (OPR3) is the isoenzyme involved in jasmonate biosynthesis 总被引:17,自引:0,他引:17
In addition to OPR1 and OPR2, two isoenzymes of 12-oxophytodienoate reductase, a third isoform (OPR3) has recently been identified
in Arabidopsis thaliana (L.) Heynh. The expression of the OPR3 gene is induced not only by a variety of stimuli, such as touch, wind, wounding, UV-light and application of detergent, but
also by brassinosteroids. The three enzymes were expressed in a functional form in Escherichia coli, and OPR2 was additionally expressed in insect cell cultures and overexpressed in A. thaliana. Substrate conversion was analyzed using a stereospecific assay. The results show that OPR3 effectively converts the natural
(9S,13S)-12-oxophytodienoic acid [K
m = 35 μM, V
max 53.7 nkat (mg protein)−1] to the corresponding 3-2(2′(Z)-pentenyl) cyclopentane-1-octanoic acid (OPC-8:0) stereoisomer while OPR1 and OPR2 convert
(9S,13S)-12-oxophytodienoic acid with greatly reduced efficiency compared to OPR3. Thus, OPR3 is the isoenzyme relevant for
jasmonate biosynthesis.
Received: 21 October 1999 / Accepted: 10 December 1999 相似文献
18.
A cDNA clone (GenBank Accession No. AY835398) encoding a sesquiterpene synthase, (E)-β-farnesene synthase, has been isolated from Artemisia annua L. It contains a 1746-bp open reading frame coding for 574 amino acids (66.9 kDa) with a calculated pI = 5.03. The deduced amino acid sequence is 30-50% identical with sequences of other sesquiterpene synthases from angiosperms. The recombinant enzyme, produced in Escherichia coli, catalyzed the formation of a single product, β-farnesene, from farnesyl diphosphate. The pH optimum for the recombinant enzyme is around 6.5 and the Km- and kcat-values for farnesyl diphosphate, is 2.1 μM and 9.5 × 10−3 s−1, respectively resulting in the efficiency 4.5 × 10−3 M−1 s−1. The enzyme exhibits substantial activity in the presence of Mg2+, Mn2+ or Co2+ but essentially no activity when Zn2+, Ni2+ or Cu2+ is used as cofactor. The concentration required for maximum activity are estimated to 5 mM, 0.5 mM and <10 μM for Mg2+, Co2+ or Mn2+, respectively. Geranyl diphosphate is not a substrate for the recombinant enzyme. 相似文献
19.
DMNT biosynthesis was proposed to proceed via (E)-nerolidol in plants a decade ago. However, (E)-nerolidol function as airborne signal/substrate for in-vivo biosynthesis of DMNT remains to be investigated and the regulation of DMNT production and emission is largely unknown. We address both of these aspects using Achyranthes bidentata model plant in conjunction with deuterium-labeled d(5)-(E)-nerolidol, headspace, GC-FID, and GC/MS-based absolute quantification approaches. We demonstrate that airborne (E)-nerolidol is specifically metabolized in-vivo into DMNT emission, but requires airborne VOC MeJA or predator herbivore as additional environmental signal. In addition, we provide new insight into the complex regulation underlying DMNT emission, and highlight the importance of studying multiple environmental factors on emission patterns of plant VOCs and their mechanistic regulation. 相似文献
20.
Production of geranylgeraniol on overexpression of a prenyl diphosphate synthase fusion gene in Saccharomyces cerevisiae 总被引:1,自引:0,他引:1
Chikara Ohto Masayoshi Muramatsu Shusei Obata Eiji Sakuradani Sakayu Shimizu 《Applied microbiology and biotechnology》2010,87(4):1327-1334
An acyclic diterpene alcohol, (E,E,E)-geranylgeraniol (GGOH), is one of the important compounds used as perfume and pharmacological agents. A deficiency of squalene
(SQ) synthase activity allows yeasts to accumulate an acyclic sesquiterpene alcohol, (E,E)-farnesol, in their cells. Since sterols are essential for the growth of yeasts, a deficiency of SQ synthase activity makes
the addition of supplemental sterols to the culture media necessary. To develop a GGOH production method not requiring any
supplemental sterols, we overexpressed HMG1 encoding hydroxymethylglutaryl-CoA reductase and the genes of two prenyl diphosphate synthases, ERG20 and BTS1, in Saccharomyces cerevisiae. A prototrophic diploid coexpressing HMG1 and the ERG20-BTS1 fusion accumulated GGOH with neither disruption of the SQ synthase gene nor the addition of any supplemental sterols. The
GGOH content on the diploid cultivation in a 5-l jar fermenter reached 138.8 mg/l under optimal conditions. 相似文献