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1.
Hiroshi Nakano Satoshi Morita Hideyuki Shigemori Koji Hasegawa 《Plant Growth Regulation》2006,48(3):215-219
When seedlings of lettuce, cress, rice and wheat were incubated with the leachate of wheat straw, the roots growth of lettuce
and garden cress were particularly inhibited. The leachate of wheat straw (100 g eq./l) showed 80.5 and 79.4% inhibition for
lettuce and cress roots, respectively. The inhibitory activity was stronger as the concentration of wheat straw leachate was
greater. This result indicates that allelochemical(s) inhibiting the roots growth of lettuce and cress are leached from the
wheat straw into the water. Two potent compounds were isolated from the leachate of the wheat straw and identified as syringoylglycerol
9-O-β-d-glucopyranoside and l-tryptophan by spectral analyses. Syringoylglycerol 9-O-β-d-glucopyranoside inhibited the roots growth of lettuce and cress at concentrations greater than 0.1 and 10.0 μM, respectively.
On the other hand, l-tryptophan inhibited the roots growth of lettuce and cress at concentrations greater than 0.1 and 1.0 μM, respectively. The
content of syringoylglycerol 9-O-β-d-glucopyranoside and l-tryptophan in the leachate of wheat straw (100 g eq./l) was 18.4 ± 0.7 and 6.2 ± 0.6 μM, respectively. Syringoylglycerol
9-O-β-d-glucopyranoside (18.4 μM) showed 21.5 and 13.5% inhibition in the lettuce and cress roots assay, respectively. On the other
hand, 6.2 μM of l-tryptophan showed 47.5 and 35.0% inhibition in the lettuce and cress roots assay, respectively. These results suggested that
l-tryptophan may be a major contributor to the allelopathy in aqueous leachate of wheat straw and syringoylglycerol 9-O-β-d-glucopyranoside may be a minor contributor. 相似文献
2.
Nariyuki Ishikura Shinobu Nakamura Masami Mato Kazumi Yamamoto 《Journal of plant research》1992,105(1):83-94
An enzyme,S-adenosyl-l-methionine: flavonoid 7-O-methyltransferase (F7OMT), catalyzing the transfer of the methyl group fromS-adenosyl-l-methionine (SAM) to the 7 position of sophoricoside (5, 7, 4′-trihydroxyisoflavone 4′-O-glucoside) and some of the other flavonoids, was detected in extracts from leaves ofPrunus x yedoensis, and it was partially purified (about 203-fold) by a combination of gel filtration and ion-exchange column chromatographies.
F7OMT was isolated as a soluble enzyme with a pH optimun of 7.5 in K-phosphate buffer. The molecular mass of F7OMT, which
had an isoelectric point at pH 4.1, was estimated by elution from a column of Sephadex G-100 to be about 36 kDa. The activity
of F7OMT was stimulated by 14 mM 2-Co2+ and reagents that react with sulfhydryl groups. The apparentKm values for sophoricoside, its aglycone genistein (5, 7, 4′-trihydroxyisoflavone) and quercetin were 1.49, 2.19 and 1.89 μM,
respectively. The apparentKm value for SAM as methyl donor was 2.08 mM. The specificity of F7OMT for methyl acceptors was not strict; flavonols, flavanones
and flavanonols in addition to isoflavones served as methyl acceptor.
An examination ofP. x yedoensis leaves during spring and autumn showed variations in the activities of F7OMT and UDP-glucose: isoflavone 4′-O-glucosyltransferase (I4′ GT). The activities of F7OMT and I4′GT increased in enlarging leaf tissues and then markedly declined
when the leaves approached maturation. In autumn leaves F7OMT activity was scarcely detected, but a small peak of I4′GT activity
was observed during autumnal reddening. 相似文献
3.
Production of the benzophenanthridine alkaloids in Eschscholtzia californica suspension cell cultures was optimized by adding 0.5 mg methyl jasmonate (MJ) and 0.02 mg salicylic acid (SA)/g FCW after
7 days cultivation. Sanguinarine reached 24 mg/g DCW by such treatment; 10 times higher than in control cell cultures. MJ
and SA induced expression of berberine bridge enzyme and 3′-hydroxy-(S)-N-methylcoclaurine-4′-O-methyltransferase, respectively. MJ plus SA induced over-expression of both enzymes. 相似文献
4.
Cellulase production on glucose-based media by the UV-irradiated mutants of Trichoderma reesei 总被引:2,自引:0,他引:2
Masakazu Ike Jeung-yil Park Mine Tabuse Ken Tokuyasu 《Applied microbiology and biotechnology》2010,87(6):2059-2066
From 22,791 mutants of a cellulase hyper-producing strain of Trichoderma reesei (Hypocrea jecorina), ATCC66589, as the parent, we selected two mutants, M2-1 and M3-1, that produce cellulases in media containing both cellulose
and glucose. The mutation enabled the mutants to produce cellulases, which were measured as p-nitrophenyl β-d-lactopyranoside-hydrolyzing activities, in media with glucose as a sole carbon source, although M2-1 exhibited different
sensitivities to glucose from M3-1. When the mutants were grown for 8 days on a medium with cellulose as a sole carbon source,
the filter-paper-degrading activities (FPAs) per gram of cellulose were 257 and 281 U for M2-1 and M3-1, respectively, values
that were 1.1–1.2 times higher than that of the parental strain. Cellulase production by M2-1 and M3-1 on a medium with a
continuously fed mixture of glucose and cellobiose resulted in 214 and 210 U of FPA/gram carbon sources, respectively, whereas
less efficient production (140 U of FPA/gram carbon source) was achieved by the parental strain. The improved cellulase productivity
of the mutants allows us to use glucose as a carbon source for efficient on-site production of cellulases with quality/quantity-controlled feeding of soluble carbon sources and inducers. 相似文献
5.
Effect of Strontium Ranelate on Hydrogen Peroxide-Induced Apoptosis of CRL-11372 Cells 总被引:2,自引:0,他引:2
Senkoylu A Yilmaz A Ergun MA Ilhan MN Simsek A Altun N Bolukbasi S Menevse S 《Biochemical genetics》2008,46(3-4):197-205
In vitro and in vivo studies have proven strontium to be an osteoinductive trace element. The effect of strontium ranelate
(SR) on H2O2-induced apoptosis of CRL-11372 cells and optimization of its anti-apoptotic dose were the aims of this study. After 1 h of
pretreatment with SR 1 μM, 50 μM, 100 μM, 500 μM, and 1,000 μM concentrations, CRL-11372 osteoblasts were exposed to 100 μM H2O2 for periods of 6–12 h. The same experiments were repeated without H2O2. The apoptotic index and viability of cells were assessed quantitatively with a fluorescent dye and qualitatively with agarose
gel electrophoresis. Concentrations of 1–100 μM of SR with a 6-h treatment and only 1 μM concentration with a 12-h treatment
inhibited the apoptotic effect of H2O2 on cultured osteoblasts significantly (P < 0.05). SR was shown to inhibit H2O2-induced apoptosis of CRL-11372 cells in a dose-dependent manner. 相似文献
6.
Wei XJ Wu J Ni YD Lu LZ Zhao RQ 《In vitro cellular & developmental biology. Animal》2011,47(10):735-741
Previous studies have shown that the in ovo injection of equol can markedly improve the water-holding capacity of muscles
of broilers chickens at 7 wk of age through promotion of the antioxidant status. We aimed to investigate directly the antioxidant
effects of equol on muscle cells in broilers. Muscle cells were separated from leg muscle of embryos on the 11th day of incubation
and treated with equol and H2O2, either alone or together. Cells were pretreated with medium containing 1, 10, or 100 μM equol for 1 h prior to the addition
of 1 mM H2O2 for a further 1 h. Photomicrographs of cells were obtained. Cell viability, malondialdehyde (MDA) content, and L-lactate
dehydrogenase (LDH) activity in the cell supernatant, as well as intracellular total superoxide dismutase (T-SOD) and glutathione
peroxidase (GSH-Px) activities were determined. Treatment with 1 mM H2O2 caused serious damage to cells, indicated by comets with no clear head region but a very apparent tail of DNA fragments.
Pretreatment with low (1 μM) but not high concentrations of equol (10 μM) inhibited cell damage, while 100 μM equol caused
more serious damage than H2O2 alone. Pretreatment with 1 μM equol had no effect on cell viability, while pretreatment with 10 and 100 μM equol significantly
decreased cell viability in a dose-dependent manner. Compared with H2O2 alone, pretreatment with low-dosage equol markedly decreased LDH activity and MDA production in the supernatant, significantly
increased intracellular T-SOD activity (P < 0.05) and tended to increase intracellular GSH-Px activity (0.05 < P < 0.1). Pretreatment with high-dosage equol (10 and 100 μM) significantly enhanced LDH activity, but had no effect on MDA
content, T-SOD or GSH-Px activity induced by H2O2, except for an obvious increase in GSH-Px activity caused by 10 μM equol. These results indicate that equol at low dosage
can prevent skeletal muscle cell damage induced by H2O2, while pretreatment with high-dosage equol shows a synergistic effect with H2O2 in inducing cell damage. 相似文献
7.
Cigang Yu Haidong Xu Guodong Huang Ting Chen Guiyou Liu Nan Chai Yin Ji Siyuan Wang Yijun Dai Sheng Yuan 《Applied microbiology and biotechnology》2010,86(3):863-870
The main product of the conversion of puerarin by unpermeabilized cells of bacterium Microbacterium oxydans CGMCC 1788 was puerarin-7-O-glucoside (241 ± 31.9 μM). Permeabilization with 40% ethanol could not increase conversion yield, whereas it resulted in
change of main product; a previous trace product became a main product (213 ± 48.0 μM) which was identified as a novel puerarin-7-O-fructoside by electrospray ionization time-of-flight MS, 13C NMR, 1H NMR, and GC-MS analysis of sugar composition, and puerarin-7-O-glucoside became a trace product (14.8 ± 5.4 μM). However, the extract from cells of M. oxydans CGMCC 1788 permeabilized with ethanol converted puerarin to form 113.9 ± 27.7 μM puerarin-7-O-glucoside and 187.8 ± 29.5 μM puerarin-7-O-fructoside under the same conditions. When unpermeabilized intact cells were recovered and used repeatedly for the conversion
of puerarin, with increase of reuse times, the yield of puerarin-7-O-glucoside gradually decreased, whereas the yield of puerarin-7-O-fructoside increased gradually in the conversion mixture. The main product of the conversion of puerarin by the tenth recycled
unpremerbilized cells was puerarin-7-O-fructoside (288.4 ± 24.0 μM). Therefore, the change of permeability of cell membrane of bacterium M. oxydans CGMCC 1788 contributed to the change of conversion of the product’s composition. 相似文献
8.
Maeda-Yamamoto M Ema K Tokuda Y Monobe M Tachibana H Sameshima Y Kuriyama S 《Cytotechnology》2011,63(2):171-179
Tea polyphenols, e.g., (-)-epigallocatechin-3-O-(3-O-methyl gallate (EGCG3”Me), (-)-epigallocatechin-3-O-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin-3-O-gallate (ECG), and (-)-epicatechin (EC), are believed to be responsible for the beneficial effects of tea. ‘Benifuuki’, a
tea (Camellia sinensis L.) cultivar grown in Japan, is rich in the anti-allergic molecule epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3”Me). Pulverized Benifuuki green tea powder (BGP) is more widely distributed than leaf tea in Japan.
Japanese people mix their pulverized tea with water directly, whereas it is common to drink leaf tea after extraction. However,
few studies of the effects of BGP particle size on polyphenol bioavailability have been performed. This study was conducted
to investigate the absorption of catechins in rats after the intragastric administration of Benifuuki green tea. Therefore,
we assessed the plasma concentrations of catechins following the ingestion of BGP with different mean particle sizes (2.86,
18.6, and 76.1 μm) or Benifuuki green tea infusion (BGI) as a control in rats. The bioavailabilities of EGCG3”Me, EGCG, ECG,
EGC, and EC were analyzed after the oral administration of a single dose of Benifuuki green tea (125 mg/rat) to rats. The
plasma concentrations of tea catechins were determined by HPLC analysis combined with of electrochemical detection (ECD) using
a coulometric array. The AUC (area under the drug concentration versus time curve; min μg/mL) of ester-type catechins (EGCG3”Me,
EGCG, and ECG) for the BGP 2.86 μm were significantly higher than those in the infusion and 18.6 and 76.1 μm BGP groups, but
the AUC of free-type catechins (EGC and EC) showed no differences between these groups. Regarding the peak plasma level of
EGCG3”Me adjusted for intake, BGP 2.86 μm and BGI showed higher values than the BGP 18.6 and 76.1 μm groups, and the peak
plasma levels of the other catechins displayed the same tendency. The present study demonstrates that the bioavailability
of ester-type catechins (EGCG and ECG) can be improved by reducing the particle size of green tea, but the plasma level of
EGCG3”Me in the BGI group was similar to that in the BGP 2.86 μm group. This result suggests that drinking Benifuuki green
tea with a particle size of around 2 μm would deliver the anti-allergic EGCG3”Me and the anti-oxidant EGCG efficiently. 相似文献
9.
10.
Deoxysugar, 2′, 3′, 4′-tri-O-methylrhamnose is an essential structural component of spinosyn A and D, which are the active ingredients of the commercial
insect control agent, Spinosad. The spnH gene, which was previously assigned as a rhamnose O-methyltransferase based on gene sequence homology, was cloned from the
wild-type Saccharopolyspora spinosa and from a spinosyn K-producing mutant that was defective in the 4′-O-methylation of 2′, 3′-tri-O-methylrhamnose. DNA sequencing confirmed a mutation resulting in an amino acid substitution of G-165 to A-165 in the rhamnosyl
4′-O-methyltransferase of the mutant strain, and the subsequent sequence analysis showed that the mutation occurred in a highly
conserved region of the translated amino acid sequence. Both spnH and the gene defective in 4′-O-methylation activity (spnH165A) were expressed heterologously in E. coli and were then purified to homogeneity using a His-tag affinity column. Substrate bioconversion studies showed that the enzyme
encoded by spnH, but not spnH165A, could utilize spinosyn K as a substrate. When the wild-type spnH gene was transformed into the spinosyn K-producing mutant, spinosyn A production was restored. These results establish that
the enzyme encoded by the spnH gene in wild-type S. spinosa is a rhamnosyl 4′-O-methyltransferase that is responsible for the final rhamnosyl methylation step in the biosynthesis of spinosyn A. 相似文献
11.
A UDP-glucose: anthocyanin 3′,5′-O-glucosyltransferase (UA3′5′GT) (EC 2.4.1.-) was purified from the petals of Clitoria ternatea L. (Phaseoleae), which accumulate polyacylated anthocyanins named ternatins. In the biosynthesis of ternatins, delphinidin
3-O-(6″-O-malonyl)-β-glucoside (1) is first converted to delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′-O-β-glucoside (2). Then 2 is converted to ternatin C5 (3), which is delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′,5′-di-O-β-glucoside. UA3′5′GT is responsible for these two steps by transferring two glucosyl groups in a stepwise manner. Its substrate
specificity revealed the regioselectivity to the anthocyanin′s 3′- or 5′-OH groups. Its kinetic properties showed comparable
k
cat values for 1 and 2, suggesting the subequality of these anthocyanins as substrates. However, the apparent K
m value for 1 (3.89 × 10−5 M), which is lower than that for 2 (1.38 × 10−4 M), renders the k
cat/K
m value for 1 smaller, making 1 catalytically more efficient than 2. Although the apparent K
m value for UDP-glucose (6.18 × 10−3 M) with saturated 2 is larger than that for UDP-glucose (1.49 × 10−3 M) with saturated 1, the k
cat values are almost the same, suggesting the UDP-glucose binding inhibition by 2 as a product. UA3′5′GT turns the product 2 into a substrate possibly by reversing the B-ring of 2 along the C2-C1′ single bond axis so that the 5′-OH group of 2 can point toward the catalytic center.
K. Kogawa, N. Kato, K. Kazuma, and N. Noda contributed equally to this work. 相似文献
12.
B. Vinterhalter T. Janković K. Šavikin R. Nikolić D. Vinterhalter 《Plant Cell, Tissue and Organ Culture》2008,94(3):329-335
Shoot cultures of Gentianella austriaca (A. & J. Kerner) Dostal established from seedling epicotyls were maintained on MS medium supplemented with 2.22 μM BA and
0.54 μM NAA. A characteristic feature of these cultures was precocious flowering, which appeared in all rapidly elongating
shoots. Flower development arrested shoot elongation and multiplication of shoot cultures. Continuous shoot propagation was
possible only by use of small axillary or adventitious buds as explants for subculturing. Flowering could not be suppressed
by GA3 addition or by cultivation in short-day conditions. The highest rooting percentage (47.3% with 7.83 roots per explant) was
achieved on media with 4.92 μM IBA. Shoot cultures contained the same types of secondary metabolites as plants from nature.
Xanthones were the major constituents, with DMB (demethylbellidifolin), DGL (demethylbellidifolin-8-O-glucoside) and BGL (bellidifolin-8-O-glucoside) present at roughly two times lower concentrations than in samples from nature. Secondary metabolite production
was strongly affected by the presence of BA in the medium. 相似文献
13.
Nisreen A. AL-Quraan Robert D. Locy Narendra K. Singh 《Plant biotechnology reports》2011,5(3):225-234
Arabidopsis mutants with T-DNA insertion in seven calmodulin genes (CAM) were used to determine the specific role of CAM in the tolerance of plants to oxidative stress induced by paraquat and hydrogen
peroxide (H2O2) treatments. Arabidopsis calmodulin mutants (cam) were screened for seedling growth, seed germination, induced oxidative damage, and levels of γ-aminobutyric acid (GABA)
shunt metabolites. Only the cam5-4 and cam6-1 mutants exhibited an increased sensitivity to paraquat and H2O2 during seed germination and seedling growth. In response to treatments with 3 μM paraquat and 1 mM H2O2, only the cam5-4, cam6-1 mutants showed significant changes in malonaldehyde (MDA) levels in root and shoot tissues, with highly increased levels
of MDA. In terms of the GABA shunt metabolites, GABA was significantly elevated in root and shoot tissues in response to the
paraquat treatments in comparison to alanine and glutamate, while the levels of all shunt metabolites increased in root tissue
but not in the shoot tissue following the H2O2 treatments. GABA, alanine and glutamate levels were significantly increased in root and shoot of the cam1, cam4, cam5-4, and cam6-1 mutants in response to paraquat (0.5, 1 and 3 μM), while they were increased only in the root tissue of the cam1, cam4, cam5-4, and cam6-1 mutants in response to H2O2 (200 and 500 μM, 1 mM). These data show that the cam5-4 and cam6-1 mutants were sensitive to the induced oxidative stress treatments in terms of seed germination, seedling growth, and oxidative
damage. The accumulation of GABA shunt metabolites as a consequence of the induced oxidative stress treatments (paraquat and
H2O2 treatments) suggests that the GABA shunt pathway and the accumulation of GABA metabolites may contribute in antioxidant machinery
associated with reactive oxygen species and in the acquisition of tolerance in response to induced oxidative stress in Arabidopsis seedlings. 相似文献
14.
Reducing blood glucose level in TIDM mice by orally administering the silk glands of transgenic hIGF-I silkworms 总被引:2,自引:0,他引:2
Cong L Cao G Renyu X Zhonghua P Xiaojian Z Zhou W Gong C 《Biochemical and biophysical research communications》2011,411(4):721-725
Protein O-mannosyltransferase 1 (POMT1) and its homolog, POMT2, are responsible for the catalysis of the first step in O-mannosyl glycan synthesis. Mutations in their genes are associated with a type of congenital muscular dystrophy called Walker-Warburg syndrome. Arg64, Glu78 and Arg138 in the N-terminus region of ScPmt1p, a POMT homolog in Saccharomyces cerevisiae, are important for transferase activity. Arg138 is also essential for complex formation with ScPmt2p. Here we examined the effects of replacing the corresponding residues in human POMT1 and POMT2 with Ala on complex formation and enzymatic activity. The human POMT1 mutants lost almost all transferase activity while the POMT2 mutants retained enzymatic activity. Neither mutant lost its ability to form complexes with the native counter component. These results indicate that ScPmtps and human POMTs have different mechanisms of complex formation. They also suggest that human POMT1 and POMT2 have discrete functions since the effect of amino acid substitutions on enzymatic activity are different. 相似文献
15.
Expression of a soluble flavone synthase allows the biosynthesis of phytoestrogen derivatives in Escherichia coli 总被引:3,自引:0,他引:3
Flavones are plant secondary metabolites with potent pharmacological properties. We report the functional expression of FSI,
a flavonoid 2-oxoglutarate-dependent dioxygenase-encoding flavone synthase from parsley in Escherichia coli. This expression allows the biosynthesis of various flavones from phenylpropanoid acids in recombinant E. coli strains simultaneously expressing five plant-specific flavone biosynthetic genes. The gene ensemble consists of 4CL-2 (4-coumarate:CoA ligase) and FSI (flavone synthase I) from parsley, chsA (chalcone synthase) and chiA (chalcone isomerase) from Petunia hybrida, and OMT1A (7-O-methyltransferase) from peppermint. After a 24-h cultivation, the recombinant E. coli produces significant amounts of apigenin (415 μg/l), luteolin (10 μg/l), and genkwanin (208 μg/l). The majority of the flavone
products are excreted in the culture media; however, 25% is contained within the cells. The metabolic engineering strategy
presented demonstrates that plant-specific flavones are successfully produced in E. coli for the first time by incorporating a soluble flavone synthase confined only in Apiaceae. 相似文献
16.
Soltani F Mosaffa F Iranshahi M Karimi G Malekaneh M Haghighi F Behravan J 《Cell biology and toxicology》2009,25(3):291-296
The protective properties of a prenylated coumarin, umbelliprenin (UMB), on the human lymphocytes DNA lesions were tested.
Lymphocytes were isolated from blood samples taken from healthy volunteers. DNA breaks and resistance to H2O2-induced damage were measured using a single-cell microgel electrophoresis technique under alkaline conditions (comet assay).
Human lymphocytes were incubated in UMB (10, 25, 50, 100, 200, and 400 μM) alone or a combination of different concentrations
of UMB (10, 25, 50, 100, 200, and 400 μM) and 25 μM H2O2. Untreated cells, ascorbic acid (AA; 25, 50, 100, 200, and 400 μM) and H2O2 (25 μM) were considered as negative control, positive control, and the standard antioxidant agent for our study, respectively.
Single cells were analyzed with “TriTek Cometscore version 1.5” software. The DNA damage was expressed as percent tail DNA.
UMB exhibited a concentration-dependent increase in protection activity against DNA damage induced by 25 μM H2O2 (from 67.28% to 39.17%). The antigenotoxic activity of AA, in the range 0–50 μM, was greater than that of UMB. However, no
significant difference (p > 0.05) in the protective activity was found between UMB and AA at concentrations of approximately higher than 50 μM. 相似文献
17.
Mauji Ram M. A. Khan Prabhakar Jha Salim Khan Usha Kiran M. M. Ahmad Saleem Javed M. Z. Abdin 《Acta Physiologiae Plantarum》2010,32(5):859-866
In vivo modulation of HMG-CoA reductase (HMGR) activity and its impact on artemisinin biosynthesis as well as accumulation
were studied through exogenous supply of labeled HMG-CoA (substrate), labeled MVA (the product), and mevinolin (the competitive
inhibitor) using twigs of Artemisia annua L. plants collected at the pre-flowering stage. By increasing the concentration (2–16 μM) of HMG-CoA (3-14C), incorporation of labeled carbon into artemisinin was enhanced from 7.5 to 17.3 nmol (up to 130%). The incorporation of
label (14C) into MVA and artemisinin was inhibited up to 87.5 and 82.9%, respectively, in the presence of 200 μM mevinolin in incubation
medium containing 12 μM HMG-CoA (3-14C). Interestingly, by increasing the concentration of MVA (2-14C) from 2 to 18 μM, incorporation of label (14C) into artemisinin was enhanced from 10.5 to 35 nmol (up to 233%). When HMG-CoA (3-14C) concentration was increased from 12 to 28 μM in the presence of 150 μM mevinolin, the inhibitions in the incorporation
of label (14C) into MVA and artemisinin were, however, reversed and the labels were found to approach their values in twigs fed with 12 μM
HMG-CoA (3-14C) without mevinolin. In another experiment, 14.2% inhibition in artemisinin accumulation was observed in twigs in the presence
of 175 μM fosmidomycin, the competitive inhibitor of 1-deoxy-d-xylulose 5-phosphate reductase (DXR). HMG-CoA reductase activity and artemisinin accumulation were also increased by 18.6
to 24.5% and 30.7 to 38.4%, respectively, after 12 h of treatment, when growth hormones IAA (100 ppm), GA3 (100 ppm) and IAA + GA3 (50 + 50 ppm) were sprayed on A. annua plants at the pre-flowering stage. The results obtained in this study, hence, demonstrate that the mevalonate pathway is
the major contributor of carbon supply to artemisinin biosynthesis and HMGR limits artemisinin synthesis and its accumulation
in A. annua plants. 相似文献
18.
Hisashi Kato-Noguchi Yoshiko Fushimi Yukitoshi Tanaka Toshiaki Teruya Kiyotake Suenaga 《Plant Growth Regulation》2011,65(2):299-304
Since red pine (Pinus densiflora Sieb. et Zucc.) often forms sparse forest floors where herbaceous plants do not grow well, allelopathy of red pine was investigated.
A growth inhibitory substance was isolated from an aqueous methanol extract of red pine needles and determined by spectral
data as abscisic acid-β-d-glucopyranosyl ester (ABA-GE). This substance inhibited root and shoot growth of cress and E. crus-galli seedlings at concentrations greater than 0.1 μM. The concentrations required for 50% growth inhibition on roots and shoots
of cress were 0.23 and 0.61 μM, respectively, and those of E. crus-galli were 1.1 and 2.8 μM, respectively. The activity of ABA-β-d-glucosidase, which liberates free ABA from ABA-GE, in cress and E. crus-galli seedlings was 13–29 nmol mg−1 protein min−1. Endogenous concentration of ABA-GE in the pine needles was 4.1–21.5 μmol kg−1 and the concentration in soil water of the pine forest was 2.5 μM. The effectiveness of ABA-GE on growth inhibition and the
occurrence of ABA-GE in pine needles and soil water suggest ABA-GE may play an important role in the allelopathy of red pine
resulting in the formation of sparse forest floors. 相似文献
19.
The effect of the two synthetic elicitors coronalon and indanoyl-isoleucine and of methyl jasmonate (MeJA) on the accumulation
and biosynthesis of lignans by cell suspension cultures of Linum nodiflorum (Linaceae) was investigated. The production of 6-methoxypodophyllotoxin (MPTOX) could be increased more than tenfold, the
maximal content reaching up to over 2.5% of the cell dry weight. The highest yield was achieved by administering 50 μM of
the synthetic elicitors on the fourth day and extracting the products on the tenth day of the culture period. An additional
lignan accumulated in elicitor-treated cultures. Its structure was elucidated by extensive 1D and 2D NMR measurements, revealing
its identity as 5′-demethoxy-MPTOX (5′-dMPTOX). Its average content amounted up to over 5% of the cell dry weight. Growth
was only slightly affected by the addition of the elicitors. Methyl jasmonate exerted a moderate stimulating effect on the
L. nodiflorum cells with MPTOX and 5′-dMPTOX contents going up to 1.4 and 2.1% of the cell dry weight, respectively. The activities of
deoxypodophyllotoxin 6-hydroxylase and β-peltatin 6-O-methyltransferase, two enzymes involved in MPTOX biosynthesis, were increased up to 21.9-fold and 14.6-fold, respectively,
in the treated cultures. 相似文献
20.
Indole-3-butyric acid at 25 μM with methyl jasmonate (MJ) at 100 μM in Panax ginseng synergistically stimulated both root growth and ginsenoside accumulation compared with 100 μM MJ alone. Productivity of ginsenoside
was 10 mg l−1 d−1 compared to 7.3 mg l−1 d−1 with MJ elicitation alone. 相似文献