TY  - JOUR
AB  - Ubiquinone (Coenzyme Q) is a vital respiratory cofactor and antioxidant in eukaryotes. The recent discovery that kaempferol serves as a precursor for ubiquinone's benzenoid moiety both challenges the conventional view of flavonoids as specialized metabolites, and offers new prospects for engineering ubiquinone in plants. Here, we present evidence that Arabidopsis thaliana mutants lacking kaempferol 3-O-rhamnosyltransferase (ugt78d1) and kaempferol 3-O-glucosyltransferase (ugt78d2) activities display increased de novo biosynthesis of ubiquinone and increased ubiquinone content. These data are congruent with the proposed model that unprotected C-3 hydroxyl of kaempferol triggers the oxidative release of its B-ring as 4-hydroxybenzoate, which in turn is incorporated into ubiquinone. Ubiquinone content in the ugt78d1/ugt78d2 double knockout represented 160% of wild-type level, matching that achieved via exogenous feeding of 4-hydroxybenzoate to wild-type plants. This suggests that 4-hydroxybenzoate is no longer limiting ubiquinone biosynthesis in the ugt78d1/ugt78d2 plants. Evidence is also shown that the glucosylation of 4-hydroxybenzoate as well as the conversion of the immediate precursor of kaempferol, dihydrokaempferol, into dihydroquercetin do not compete with ubiquinone biosynthesis in A. thaliana.
AU  - Soubeyrand, E.*
AU  - Latimer, S.*
AU  - Bernert, A.C.*
AU  - Keene, S.A.*
AU  - Johnson, T.S.*
AU  - Shin, D.*
AU  - Block, A.K.*
AU  - Colquhoun, T.A.*
AU  - Schäffner, A.
AU  - Kim, J.*
AU  - Basset, G.J.*
C1  - 61648
C2  - 50368
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
TI  - 3-O-glycosylation of kaempferol restricts the supply of the benzenoid precursor of ubiquinone (Coenzyme Q) in Arabidopsis thaliana.
JO  - Phytochemistry
VL  - 186
PB  - Pergamon-elsevier Science Ltd
PY  - 2021
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - In the plant kingdom beta-glucosidases (BGLUs) of the glycosidase hydrolase family 1 have essential function in primary metabolism and are particularly employed in secondary metabolism. They are essential for activation in two-component defence systems based on stabilisation of reactive compounds by glycosylation. Based on de novo assembly we isolated and functionally characterised BGLUs expressed in leaves of Lamium galeobdolon (LgGLUs). LgGLU1 could be assigned to hydrolysis of the benzoxazinoid GDIBOA (2,4-dihydroxy-1,4-benzoxazin-3-one glucoside).Within the Lamiaceae L. galeobdolon is distinguished by the presence GDIBOA in addition to the more common iridoid harpagide. Although LgGLU1 proved to be promiscuous with respect to accepted substrates, harpagide hydrolysis was not detected. Benzoxazinoids are characteristic defence compounds of the Poales but are also found in some unrelated dicots. The benzoxazinoid specific BGLUs have recently been identified for the grasses maize, wheat, rye and the Ranunculaceae Consolida orientalis. All enzymes share a general substrate ambiguity but differ in detailed substrate pattern. The isolation of the second dicot GDIBOA glucosidase LgGLU1 allowed it to analyse the phylogenetic relation of the distinct BGLUs also within dicots. The data revealed long periods of independent sequence evolution before speciation.
AU  - Hannemann, L.*
AU  - Lucaciu, C.R.*
AU  - Sharma, S.
AU  - Rattei, T.*
AU  - Mayer, K.F.X.
AU  - Gierl, A.*
AU  - Frey, M.*
C1  - 54547
C2  - 45659
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
SP  - 224-233
TI  - A promiscuous beta-glucosidase is involved in benzoxazinoid deglycosylation in Lamium galeobdolon.
JO  - Phytochemistry
VL  - 156
PB  - Pergamon-elsevier Science Ltd
PY  - 2018
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - In Arabidopsis thaliana phytoalexin biosynthesis is tightly regulated. The camalexin biosynthetic gene CYP71B15/PAD3 is highly expressed in response to pathogens and specific abiotic triggers, while constitutive expression is very low. Based on this property we expressed artificial antimicrobial peptides under control of the CYP71B15 promoter avoiding potential toxic effects to the plant related to constitutive expression. Significant and substantial growth inhibition of Pseudomonas syringae was observed, demonstrating that expression of these peptides under control of a phytoalexin promoter is an effective approach for enhancement of resistance against bacterial pathogens.
AU  - Chapman, A.*
AU  - Lindermayr, C.
AU  - Glawischnig, E.*
C1  - 47734
C2  - 39491
CY  - Oxford
SP  - 76-80
TI  - Expression of antimicrobial peptides under control of a camalexin-biosynthetic promoter confers enhanced resistance against Pseudomonas syringae.
JO  - Phytochemistry
VL  - 122
PB  - Pergamon-elsevier Science Ltd
PY  - 2016
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - In Brassica napus, suppression of the key biosynthetic enzyme UDP-glucose:sinapic acid glucosyltransferase (UGT84A9) inhibits the biosynthesis of sinapine (sinapoylcholine), the major phenolic component of seeds. Based on the accumulation kinetics of a total of 158 compounds (110 secondary and 48 primary metabolites), we investigated how suppression of the major sink pathway of sinapic acid impacts the metabolome of developing seeds and seedlings. In UGT84A9-suppressing (UGT84A9i) lines massive alterations became evident in late stages of seed development affecting the accumulation levels of 58 secondary and 7 primary metabolites. UGT84A9i seeds were characterized by decreased amounts of various hydroxycinnamic acid (HCA) esters, and increased formation of sinapic and syringic acid glycosides. This indicates glycosylation and β-oxidation as metabolic detoxification strategies to bypass intracellular accumulation of sinapic acid. In addition, a net loss of sinapic acid upon UGT84A9 suppression may point to a feedback regulation of HCA biosynthesis. Surprisingly, suppression of UGT84A9 under control of the seed-specific NAPINC promoter was maintained in cotyledons during the first two weeks of seedling development and associated with a reduced and delayed transformation of sinapine into sinapoylmalate. The lack of sinapoylmalate did not interfere with plant fitness under UV-B stress. Increased UV-B radiation triggered the accumulation of quercetin conjugates whereas the sinapoylmalate level was not affected.
AU  - Hettwer, K.*
AU  - Böttcher, C.*
AU  - Frolov, A.*
AU  - Mittasch, J.*
AU  - Albert, A.
AU  - von Roepenack-Lahaye, E.*
AU  - Strack, D.*
AU  - Milkowski, C.*
C1  - 47807
C2  - 39500
SP  - 46-57
TI  - Dynamic metabolic changes in seeds and seedlings of Brassica napus (oilseed rape) suppressing UGT84A9 reveal plasticity and molecular regulation of the phenylpropanoid pathway.
JO  - Phytochemistry
VL  - 124
PY  - 2016
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - Sixteen compounds including dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid conjugates and dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid/1-O-flavonyl-β-d-glucopyranoside conjugates, together with other dihydroxyprenylfuranocoumarins conjugates, were isolated from the ethyl acetate extract of the fruit peels of Citrus hystrix. Some of the isolates were evaluated for their cholinesterase inhibitory activity, but only one compound possessing a 3-O-β-d-glucopyranosyl-3,5,7,4'-tetrahydroxy-6,8,3'-trimethoxyflavonol nucleus in the prenylfuranocoumarin-HMGA conjugate showed strong activity.
AU  - Seeka, C.*
AU  - Sutthivaiyakit, P.*
AU  - Youkwan, J.*
AU  - Hertkorn, N.
AU  - Harir, M.
AU  - Schmitt-Kopplin, P.
AU  - Sutthivaiyakit, S.*
C1  - 48162
C2  - 39945
CY  - Oxford
SP  - 38-49
TI  - Prenylfuranocoumarin-HMGA-flavonol glucoside conjugates and other constituents of the fruit peels of Citrus hystrix and their anticholinesterase activity.
JO  - Phytochemistry
VL  - 127
PB  - Pergamon-elsevier Science Ltd
PY  - 2016
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - The genome of Arabidopsis thaliana encodes 54 functional glutathione transferases (GSTs), classified in seven clades. Although plant GSTs have been implicated in the detoxification of xenobiotics, such as herbicides, extensive redundancy within this large gene family impedes a functional analysis in planta. In this study, a GST-deficient yeast strain was established as a system for analyzing plant GSTs that allows screening for GST substrates and identifying substrate preferences within the plant GST family. To this end, five yeast genes encoding GSTs and GST-related proteins were simultaneously disrupted. The resulting yeast quintuple mutant showed a strongly reduced conjugation of the GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). Consistently, the quintuple mutant was hypersensitive to CDNB, and this phenotype was complemented by the inducible expression of Arabidopsis GSTs. The conjugating activity of the plant GSTs was assessed by in vitro enzymatic assays and via analysis of exposed yeast cells. The formation of glutathione adducts with dinitrobenzene was unequivocally verified by stable isotope labeling and subsequent accurate ultrahigh-resolution mass spectrometry (ICR-FTMS). Analysis of Arabidopsis GSTs encompassing six clades and 42 members demonstrated functional expression in yeast by using CDNB and NBD-Cl as model substrates. Subsequently, the established yeast system was explored for its potential to screen the Arabidopsis GST family for conjugation of the fungicide anilazine. Thirty Arabidopsis GSTs were identified that conferred increased levels of glutathionylated anilazine. Efficient anilazine conjugation was observed in the presence of the phi, tau, and theta clade GSTs including AtGSTF2, AtGSTF4, AtGSTF6, AtGSTF8, AtGSTF10, and AtGSTT2, none of which had previously been known to contribute to fungicide detoxification. ICR-FTMS analysis of yeast extracts allowed the simultaneous detection and semiquantification of anilazine conjugates as well as catabolites.
AU  - Krajewski, M.P.*
AU  - Kanawati, B.
AU  - Fekete, A.
AU  - Kowalski, N.*
AU  - Schmitt-Kopplin, P.
AU  - Grill, E.*
C1  - 26168
C2  - 32103
SP  - 198-207
TI  - Analysis of Arabidopsis glutathione-transferases in yeast.
JO  - Phytochemistry
VL  - 91
PB  - Pergamon-Elsevier
PY  - 2013
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - The contribution of proteomics to the knowledge of forest tree (the most recalcitrant and almost forgotten plant species) biology is being reviewed and discussed, based on the author's own research work and papers published up to November 2010. This review is organized in four introductory sections starting with the definition of forest trees (1), the description of the environmental and economic importance (2) and its derived current priorities and research lines for breeding and conservation (3) including forest tree genomics (4). These precede the main body of this review: a general overview to proteomics (5) for introducing the forest tree proteomics section (6). Proteomics, defined as scientific discipline or experimental approach, it will be discussed both from a conceptual and methodological point of view, commenting on realities, challenges and limitations. Proteomics research in woody plants is limited to a reduced number of genera, including Pinus, Picea, Populus, Eucalyptus, and Fagus, mainly using first-generation approaches, e.g., those based on two-dimensional electrophoresis coupled to mass spectrometry. This area joins the own limitations of the technique and the difficulty and recalcitrance of the plant species as an experimental system. Furthermore, it contributes to a deeper knowledge of some biological processes, namely growth, development, organogenesis, and responses to stresses, as it is also used in the characterization and cataloguing of natural populations and biodiversity (proteotyping) and in assisting breeding programmes.
AU  - Abril, N.*
AU  - Gion, J.M.*
AU  - Kerner, R.C.
AU  - Müller-Starck, G.*
AU  - Cerrillo, R.M.*
AU  - Plomion, C.*
AU  - Renaut, J.*
AU  - Valledor, L.*
AU  - Jorrin-Novo, J.V.*
C1  - 3855
C2  - 28677
SP  - 1219-1242
TI  - Proteomics research on forest trees, the most recalcitrant and orphan plant species.
JO  - Phytochemistry
VL  - 72
IS  - 10
PB  - Elsevier
PY  - 2011
SN  - 0031-9422
ER  - 

TY  - JOUR
AU  - Pflugmacher, S.*
AU  - Schröder, P.
AU  - Sandermann, H.
C1  - 21814
C2  - 20017
SP  - 267-273
TI  - Taxonomic distribution of plant glutathione S-transferases acting on xenobiotics.
JO  - Phytochemistry
VL  - 54
PY  - 2000
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - A screening method using LC-DAD-ESI/MS was applied to the analysis of flavonoids in celery, Chinese celery, and celery seeds (Apium graveolens L. and varieties). Fifteen flavonoid glycosides were detected in the three celery materials. They were identified as luteolin 7-O-apiosylglucoside, luteolin 7-O-glucoside, apigenin 7-O-apiosylglucoside, chrysoeriol 7-O-apiosylglucoside, chrysoeriol 7-O-glucoside, and more than 10 malonyl derivatives of these glycosides. The identification of the malonyl derivatives was confirmed by their conversion into glycosides upon heating and by comparison of some of the malonates with malonates that had previously been identified in red bell pepper and parsley. The concentrations of the glycosides and the malonyl glycosides in the three materials were estimated by comparison to aglycone standards. This is the first report of the presence of these glycosylated flavonoid malonates in celery.
AU  - Eckey-Kaltenbach, H.
AU  - Heller, W.
AU  - Sonnenbichler, J.
AU  - Zetl, I.
AU  - Schäfer, W.
AU  - Ernst, D.
AU  - Sandermann, H.
C1  - 20475
C2  - 13683
SP  - 687-691
TI  - Oxidative Stress and Plant Secondary Metabolism: 6"-O-malonylapiin in Parsley.
JO  - Phytochemistry
VL  - 34
PY  - 1993
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - Spruce needle cinnamyl alcohol dehydrogenase (CAD) was induced in seedlings and four-year-old trees two-to-four-fold by ozone concentrations that did not lead to visible damage. CAD thus acted as an early biochemical ozone marker. A highly purified CAD preparation consisting of two ∼42 000 Mr subunits was prepared from spruce cell cultures. A polyclonal antibody was strongly inhibitory. The enzyme had high specificity for coniferyl alcohol and NADP+, and was also detected in spruce seedlings and spruce cambial sap.
AU  - Galliano, H.
AU  - Heller, W.E.
AU  - Sandermann, H.J.
C1  - 40318
C2  - 40059
SP  - 557-563
TI  - Ozone induction and purification of spruce cinnamyl alcohol dehydrogenase.
JO  - Phytochemistry
VL  - 32
IS  - 3
PY  - 1993
SN  - 0031-9422
ER  - 

TY  - JOUR
AB  - Leaf injury of the ozone-sensitive tobacco cultivar Bel W 3 caused by ozone treatments was prevented to a large extent by root application of putrescine, spermidine or spermine. The titres of soluble free and conjugated putrescine and spermidine were concomitantly increased two- to three-fold after putrescine or spermidine application. The amounts of putrescine and spermidine associated with cell wall or membrane pellet fractions were elevated four to six times above levels of control plants. In order to establish whether the protective effect of polyamines against ozone damage may be caused by their proposed radical scavenging properties, the reactivities of polyamines and putrescine conjugates towards hydroxyl, tert-butoxyl, sulphite radicals and superoxide anions were determined. Free polyamines showed relatively low rate constants with all types of radicals. Only putrescine conjugates with the effective radical scavengers caffeic, ferulic and p-coumaric acid had consistently high rate constants. It is concluded that scavenging of radicals by free polyamines cannot explain the protection against ozone damage observed after exogenous application.
AU  - Bors, W.
AU  - Langebartels, C.
AU  - Michel, C.
AU  - Sandermann, H.
C1  - 17483
C2  - 10389
SP  - 1589-1595
TI  - Polyamines as Radical Scavengers and Protectants against Ozone Damage.
JO  - Phytochemistry
VL  - 28
IS  - 6
PY  - 1989
SN  - 0031-9422
ER  - 

TY  - JOUR
AU  - Bors, W.
AU  - Michel, C.
AU  - Langebartels, C.
AU  - Sandermann, H.
C1  - 17451
C2  - 10357
TI  - Polyamines as Radical Scavengers and Antiozonants in Tabacco Plants: A re-evaluation.
JO  - Phytochemistry
PY  - 1988
SN  - 0031-9422
ER  -