共查询到20条相似文献,搜索用时 15 毫秒
1.
Hisashi Kato-Noguchi Yoshiko Fushimi Fukiko Kimura Maho Morita Kiyotake Suenaga 《Plant Growth Regulation》2012,68(2):171-175
An organ-specific-growth inhibitory substance was isolated from an aqueous methanol extract of red pine needles and determined by spectral data as 1-mono(16-hydroxyhexadecanoyl)glycerol. This substance inhibited root growth of cress (Lepidium sativum L.) and barnyard grass (Echinochloa crus-galli (L.) Beauv) seedlings at concentrations greater than 0.01 and 0.03???M, respectively. The concentrations required for 50?% growth inhibition on roots of cress and barnyard grass were 0.16 and 3.4???M, respectively. However, the inhibitory activity of the substance on shoots of cress and barnyard grass was very weak. The endogenous concentration of 1-mono(16-hydroxyhexadecanoyl)glycerol in the pine needles was 4.6???mol?kg?1. Two related compounds, 1-monohexadecanoylglycerol and 16-hydroxyhexadecanlic acid had no activity up to 1,000???M on cress roots and shoots. The effectiveness of 1-mono(16-hydroxyhexadecanoyl)glycerol on root growth inhibition and the occurrence of 1-mono(16-hydroxyhexadecanoyl)glycerol in pine needles suggest the substance may play an important role in the allelopathy of red pine. Root-specific-growth-inhibition by the substance may be one of the strategies for red pine to compete with neighboring plants for nutrients and space because root growth of competitive plants may be very important for their whole plant development. 相似文献
2.
Exogenously applied ABA-β-d-glucopyranosyl ester (ABA-GE) inhibited shoot growth of alfalfa (Medicago sativa L.), cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), Digitaria sanguinalis L., timothy (Pheleum pratense L.) and ryegrass (Lolium multiflorum Lam.) seedlings at concentrations greater than 0.1 μM. The growth inhibitory activity of ABA-GE on these shoots was 26–40% of
that of (+)-ABA. ABA-β-d-glucosidase activities in these seedlings were 11–31 nmol mg−1 protein min−1. These results suggests that exogenously applied ABA-GE may be absorbed by plant roots and hydrolyzed by ABA-β-d-glucosidase, and liberated free ABA may induce the growth inhibition in these plants. Thus, although ABA-GE had been thought
to be physiologically inactive ABA conjugate, ABA-GE may have important physiological functions rather than an inactive conjugated
ABA form. 相似文献
3.
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
4.
An allelopathic substance in red pine needles (Pinus densiflora) 总被引:1,自引:0,他引:1
Aqueous methanol extracts of red pine (Pinus densiflora) needles inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), ryegrass (Lolium multiflorum), timothy (Pheleum pratense), Digitaria sanguinalis and Echinochloa crus-galli. Increasing the extract concentration increased inhibition, suggesting that the pine needles may have growth inhibitory substances and possess allelopathic potential. The aqueous methanol extract of the pine needles was purified, and a main inhibitory substance was isolated and determined by spectral data as 9alpha,13beta-epidioxyabeit-8(14)en-18-oic acid. This substance inhibited root and shoot growth of cress and Echinochloa crus-galli seedlings at concentrations greater than 0.1 mM. The endogenous concentration of the substance was 0.13 mmol/kg pine needle. These results suggest that 9alpha,13beta-epidioxyabeit-8(14)en-18-oic acid may contribute to the growth inhibitory effect of the pine needles and may play an important role in the allelopathy of red pine. 相似文献
5.
Biosynthesis of six saponins (ginsenosides) in suspension culture of P. quinquefolium Z5 was investigated. Ginsenoside content in biomass reached the highest level, nearly 30 mg g−1 d.w., between 25 and 30 days of the culture. Saponins were synthesized simultaneously with cell growth but their synthesis
rate was not proportional to the growth rate. During the phase of rapid biomass multiplication, after which biomass reached
90% of its maximum yield, only half examined ginsenosides was produced. The second half of the final saponins yield was produced
during the slow growth phase, in which only 10% of biomass was grown. During the intensive growth phase the productivity of
six saponins examined per biomass (dry weight) unit was 3.4 μg mg−1 d.w. day−1, however, this parameter calculated for slow growth phase reached nearly 30 μg mg−1 d.w. day−1. There were differences in increase of the contents of six saponins determined in biomass, and it was the highest for saponins
Re (20(S)-protopanaxatriol-6-[O-α-l-rhamnopyranosyl(1 → 2)-β-d-glucopyranoside]-20-O-β-d-glucopyranoside) and Rg1 (20(S)-protopanaxatriol-6,20-di-O-β-d-glucoside). 相似文献
6.
Hisashi Kato-Noguchi Madoka Yamamoto Kazuya Tamura Toshiaki Teruya Kiyotake Suenaga Yoshiharu Fujii 《Plant Growth Regulation》2010,60(2):127-131
Aqueous methanol extracts of rattail fescue (Vulpia myuros) inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), timothy (Phleum pratense), Digitaria sanguinalis and Lolium multiflorum. Increasing the extract concentration increased the inhibition, suggesting that rattail fescue may have growth inhibitory
substances and possess allelopathic potential. The aqueous methanol extract of rattail fescue was purified and two main inhibitory
substances were isolated and identified by spectral data as (−)-3-hydroxy-β-ionone and (+)-3-oxo-α-ionol. Both substances
inhibited root and shoot growth of cress at concentrations greater than 0.3 μM. The concentrations required for 50% growth
inhibition on root and shoot growth of cress, lettuce, alfalfa, timothy, D. sanguinalis and L. multiflorum were 2.7–19.7 μM for (−)-3-hydroxy-β-ionone, and 2.1–34.5 μM for (+)-3-oxo-α-ionol. The concentration of (−)-3-hydroxy-β-ionone
and (+)-3-oxo-α-ionol, respectively, in rattail fescue was 7.8 and 3.7 μg g−1 fresh weight. Considering the endogenous level and the inhibitory activity, (−)-3-hydroxy-β-ionone and (+)-3-oxo-α-ionol
may work as allelopathic substances in rattail fescue through the growth inhibition of neighboring plant species. 相似文献
7.
M. E. Estrada-Zúñiga F. Cruz-Sosa M. Rodríguez-Monroy J. R. Verde-Calvo E. J. Vernon-Carter 《Plant Cell, Tissue and Organ Culture》2009,97(1):39-47
Plant tissue cultures represent a potential source for producing secondary metabolites. In this work, Buddleja cordata tissue cultures were established in order to produce phenylpropanoids (verbascoside, linarin and hydroxycinnamic acids),
as these metabolites are credited with therapeutic properties. Highest callus induction (76.4–84.3%) was obtained in five
treatments containing 2,4-Dichlorophenoxyacetic acid (2,4-d: 0.45–9.05 μM) with Kinetin (KIN: 2.32, 4.65 μM), whereas highest root induction (79.6%) corresponded to the α-Naphthaleneacetic
acid (9.05 μM) with KIN (2.32 μM) treatment. Verbascoside was the major phenylpropanoid produced in in vitro cultures (root,
white and green callus) [66.24–86.26 mg g−1 dry weight (DW)], while linarin and hydroxycinnamic acid production was low (0.95–3.01 mg g−1 DW). Verbascoside and linarin production were improved in cell suspension culture (116 mg g−1 DW and 8.12 mg g−1 DW, respectively). 相似文献
8.
9.
Jukka Sakari Pumpanen Jussi Heinonsalo Terhi Rasilo Kaj-Roger Hurme Hannu Ilvesniemi 《Trees - Structure and Function》2009,23(3):611-621
Carbon dioxide is released from the soil to the atmosphere in heterotrophic respiration when the dead organic matter is used
for substrates for soil micro-organisms and soil animals. Respiration of roots and mycorrhiza is another major source of carbon
dioxide in soil CO2 efflux. The partitioning of these two fluxes is essential for understanding the carbon balance of forest ecosystems and for
modelling the carbon cycle within these ecosystems. In this study, we determined the carbon balance of three common tree species
in boreal forest zone, Scots pine, Norway spruce, and Silver birch with gas exchange measurements conducted in laboratory
in controlled temperature and light conditions. We also studied the allocation pattern of assimilated carbon with 14C pulse labelling experiment. The photosynthetic light responses of the tree species were substantially different. The maximum
photosynthetic capacity (P
max) was 2.21 μg CO2 s−1 g−1 in Scots pine, 1.22 μg CO2 s−1 g−1 in Norway spruce and 3.01 μg CO2 s−1 g−1 in Silver birch seedlings. According to the pulse labelling experiments, 43–75% of the assimilated carbon remained in the
aboveground parts of the seedlings. The amount of carbon allocated to root and rhizosphere respiration was about 9–26%, and
the amount of carbon allocated to root and ectomycorrhizal biomass about 13–21% of the total assimilated CO2. The 14CO2 pulse reached the root system within few hours after the labelling and most of the pulse had passed the root system after
48 h. The transport rate of carbon from shoot to roots was fastest in Silver birch seedlings. 相似文献
10.
Kunijiro Yoshitama Tomoyuki Kawasoe Nariyuki Ishikura 《Journal of plant research》1993,106(3):223-227
From the blue seed coats ofOphiopogon jaburan, a new flavonol glycoside was isolated as needles and determined to be kaempferol 3-O-β-d-galactoside-4′-O-β-d-glucoside (OK-2) by UV and NMR spectral analyses. OK-2 and kaempfrol 3, 4′-di-O-β-d-glucoside (OK-1), which was detected previously, in the blue seed coat were present in a molar ratio of about 13:7. OK-2
was newly found as a factor causing the blueing effects on ophionin which is a main anthocyanin in the blue seed coats. The
mixture of 4.8×10−3 M OK-2 and 2.5×10−3 M ophionin in Mcllvaine's buffer solution (pH 5.6) showed stable blue color, and the absorption spectrum of the mixture showed
two absorption peaks and a shoulder in visible reasion, coinciding with that of the fresh blue seed coat. The effect of ophionin
and OK-2 co-pigmentation on the blue color of seed coat ofO. jaburan was discussed. 相似文献
11.
Federico A. Gutiérrez-Miceli Lourdes Arias Nicolás Juarez-Rodríguez Miguel Abud-Archila Aldo Amaro-Reyes Luc Dendooven 《In vitro cellular & developmental biology. Plant》2010,46(1):57-63
This paper reports on the optimum concentrations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) to stimulate callus
growth and NAA; kinetin and silver nitrate (AgNO3) for callus redifferentiation in Dianthus caryophyllus L. Meristems were excised and placed in MS medium with 30 g l−1 sucrose and 9.0 μM 2,4-d. Callus clusters were transferred to MS medium containing NAA (0, 1.7, 3.3, and 5.0 μM) and BA (0, 1.7, 3.3, and 5.0 μM)
for proliferation and to MS medium with 30 g l−1 sucrose, 2.5 g l−1 phytagel, kinetin (0, 33, and 66 μM); NAA (0, 7.95, and 15.9 μM) and AgNO3 (0, 23.54 and 47.08 μM) for shoot and root induction. Treatments were applied according to a Box–Behnken design. After callus
growth and redifferentiation, plants were incubated in the greenhouse at 18 ± 2°C for 4 wk and at 20–26°C for 4 wk. Finally,
plants were changed to near-commercial greenhouse conditions with different day (30–35°C) and night (16–24°C) temperatures.
Results showed better callus growth at higher NAA concentrations. A maximum callus weight was found with 5.0 μM NAA but without
BA. A maximum of 78% calluses with shoots was obtained with 15.9 μM NAA, 47.08 μM AgNO3, and 0.74 μM kinetin and 58% with roots with 15.7 μM NAA and 47.08 μM AgNO3, but without kinetin. The shoots obtained showed little hyperhydricity. Vigorous plants were obtained after gradual acclimatization
with an 80% survival rate under nursery conditions. 相似文献
12.
An DS Cui CH Sung BH Yang HC Kim SC Lee ST Im WT Kim SG 《Applied microbiology and biotechnology》2012,94(3):673-682
The gene encoding an α-l-arabinofuranosidase that could biotransform ginsenoside Rc {3-O-[β-d-glucopyranosyl-(1–2)-β-d-glucopyranosyl]-20-O-[α-l-arabinofuranosyl-(1–6)-β-d-glucopyranosyl]-20(S)-protopanaxadiol} to ginsenoside Rd {3-O-[β-d-glucopyranosyl-(1–2)-β-d-glucopyranosyl]-20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol} was cloned from a soil bacterium, Rhodanobacter ginsenosidimutans strain Gsoil 3054T, and the recombinant enzyme was characterized. The enzyme (AbfA) hydrolyzed the arabinofuranosyl moiety from ginsenoside
Rc and was classified as a family 51 glycoside hydrolase based on amino acid sequence analysis. Recombinant AbfA expressed
in Escherichia coli hydrolyzed non-reducing arabinofuranoside moieties with apparent K
m values of 0.53 ± 0.07 and 0.30 ± 0.07 mM and V
max values of 27.1 ± 1.7 and 49.6 ± 4.1 μmol min−1 mg−1 of protein for p-nitrophenyl-α-l-arabinofuranoside and ginsenoside Rc, respectively. The enzyme exhibited preferential substrate specificity of the exo-type
mode of action towards polyarabinosides or oligoarabinosides. AbfA demonstrated substrate-specific activity for the bioconversion
of ginsenosides, as it hydrolyzed only arabinofuranoside moieties from ginsenoside Rc and its derivatives, and not other sugar
groups. These results are the first report of a glycoside hydrolase family 51 α-l-arabinofuranosidase that can transform ginsenoside Rc to Rd. 相似文献
13.
A recombinant putative glycoside hydrolase from Caldicellulosiruptor saccharolyticus was purified with a specific activity of 12 U mg−1 by heat treatment and His-Trap affinity chromatography, and identified as a single 56 kDa band upon SDS-PAGE. The native
enzyme is a dimer with a molecular mass of 112 kDa as determined by gel filtration. The enzyme exhibited its highest activity
when debranched arabinan (1,5-α-l-arabinan) was used as the substrate, demonstrating that the enzyme was an endo-1,5-α-l-arabinanase. The K
m, k
cat, and k
cat/K
m values were 18 mg ml−1, 50 s−1, and a 2.8 mg ml−1 s−1, respectively. Maximum enzyme activity was at pH 6.5 and 75°C. The half-lives of the enzyme at 65, 70 and 75°C were 2440,
254 and 93 h, respectively, indicating that it is the most thermostable of the known endo-1,5-α-l-arabinanases. 相似文献
14.
Mahdi Mohammadian Mehrnoosh Fathi-Roudsari Nasrin Mollania Arastoo Badoei-Dalfard Khosro Khajeh 《Journal of industrial microbiology & biotechnology》2010,37(8):863-869
Laccases (benzenediol oxygen oxidoreductase; EC 1.10.3.2) have many biotechnological applications because of their oxidation
ability towards a wide range of phenolic compounds. Within recent years, researchers have been highly interested in the identification
and characterization of laccases from bacterial sources. In this study, we have isolated and cloned a gene encoding laccase
(CotA) from Bacillus sp. HR03 and then expressed it under microaerobic conditions and decreased temperature in order to obtain high amounts of
soluble protein. The laccase was purified and its biochemical properties were investigated using three common laccase substrates,
2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), syringaldazine (SGZ) and 2,6-dimethoxyphenol (2,6-DMP). K
M and k
cat were calculated 535 μM and 127 s−1 for ABTS, 53 μM and 3 s−1 for 2, 6-DMP and 5 μM and 20 s−1 for SGZ when the whole reactions were carried out at room temperature. Laccase activity was also studied when the enzyme
was preincubated at 70 and 80°C. With SGZ as the substrate, the activity was increased three-fold after 50 min preincubation
at 70°C and 2.4-fold after 10 min preincubation at 80°C. Preincubation of the enzyme in 70°C for 30 min raised the activity
four-fold with ABTS as the substrate. Also, l-dopa was used as a substrate. The enzyme was able to oxidize l-dopa with the K
M and k
cat of 1,493 μM and 194 s−1, respectively. 相似文献
15.
A recombinant putative β-galactosidase from Thermoplasma acidophilum was purified as a single 57 kDa band of 82 U mg−1. The molecular mass of the native enzyme was 114 kDa as a dimer. Maximum activity was observed at pH 6.0 and 90°C. The enzyme
was unstable below pH 6.0: at pH 6 its half-life at 75°C was 28 days but at pH 4.5 was only 13 h. Catalytic efficiencies decreased
as p-nitrophenyl(pNP)-β-d-fucopyranoside (1067) > pNP-β-d-glucopyranoside (381) > pNP-β-d-galactopyranoside (18) > pNP-β-d-mannopyranoside (11 s−1 mM−1), indicating that the enzyme was a β-glycosidase. 相似文献
16.
Minoru Tanigawa Tomomitsu Shinohara Makoto Saito Katsushi Nishimura Yuichiro Hasegawa Sadao Wakabayashi Morio Ishizuka Yoko Nagata 《Amino acids》2010,38(1):247-255
Helicobacter pylori is a microaerophilic bacterium, associated with gastric inflammation and peptic ulcers. d-Amino acid dehydrogenase is a flavoenzyme that digests free neutral d-amino acids yielding corresponding 2-oxo acids and hydrogen. We sequenced the H. pylori NCTC 11637 d-amino acid dehydrogenase gene, dadA. The primary structure deduced from the gene showed low similarity with other bacterial d-amino acid dehydrogenases. We purified the enzyme to homogeneity from recombinant Escherichia coli cells by cloning dadA. The recombinant protein, DadA, with 44 kDa molecular mass, possessed FAD as cofactor, and showed the highest activity to
d-proline. The enzyme mediated electron transport from d-proline to coenzyme Q1, thus distinguishing it from d-amino acid oxidase. The apparent K
m and V
max values were 40.2 mM and 25.0 μmol min−1 mg−1, respectively, for dehydrogenation of d-proline, and were 8.2 μM and 12.3 μmol min−1 mg−1, respectively, for reduction of Q1. The respective pH and temperature optima were 8.0 and 37°C. Enzyme activity was inhibited markedly by benzoate, and moderately
by SH reagents. DadA showed more similarity with mammalian d-amino acid oxidase than other bacterial d-amino acid dehydrogenases in some enzymatic characteristics. Electron transport from d-proline to a c-type cytochrome was suggested spectrophotometrically. 相似文献
17.
I. A. Montalbán N. De Diego E. Aguirre Igartua A. Setién P. Moncaleán 《Plant biotechnology reports》2011,5(2):177-186
This study describes for the first time in Pinus genus a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis from immature seeds of
radiata pine. Somatic embryos were obtained from embryogenic line 2162 of Pinus radiata D. Don on EDM basal medium containing 60 μM ABA and 6% sucrose. The explants used for organogenesis experiments were either
freshly collected somatic embryos or somatic embryos germinated for 1 week. Germination medium was half-strength LP medium,
supplemented with 0.2% activated charcoal. Different induction periods and BA concentrations were assayed for shoot induction.
After induction treatments, explants were elongated on the same medium used for germination stage. Rooting medium was quarter-strength
LP medium supplemented with three different auxin treatments: 1.5 mg L−1 1-naphthalene acetic acid (NAA), 1.5 mg L−1 indole-3-butyric acid (IBA) and 1 mg L−1 IBA with 0.5 mg L−1 NAA (MIX). The effect of the photon flux (120 mmol m−2 s−1 and darkness) in the first week of the explants in the rooting media was also tested. This methodology could offer an alternative
to overcome some problems associated with somatic embryogenesis such as the seasonality of embryogenic tissue (ET) initiation
or a low embryo production from the ET, a particularly important issue in the case of genetically transformed ETs. 相似文献
18.
Jiangming Mo Sandra Brown Jinghua Xue Yunting Fang Zhian Li Dejun Li Shaofeng Dong 《Ecological Research》2007,22(4):649-658
The effects of simulated N deposition on changes in mass, C, N and P of decomposing pine (Pinus massoniana) needles in a disturbed and a rehabilitated forest in tropical China were studied during a 24-month period. The objective
of the study was to test the hypothesis that litter decomposition in a disturbed forest is more sensitive to N deposition
rate than litter decomposition in a rehabilitated forest due to the relatively low nutrient status in the former as a result
of constant human disturbance (harvesting understory and litter). The litterbag method and N treatments (control, no N addition;
low-N, 5 g N m−2 year−1; medium-N, 10 g N m−2 year−1) were employed to evaluate decomposition. The results revealed that N addition increased (positive effect) mass loss rate
and C release rate but suppressed (negative effect) the release rate of N and P from decomposing needles in both disturbed
and rehabilitated forests. The enhanced needle decomposition rate by N addition was significantly related to the reduction
in the C/N ratio in decomposing needles. However, N availability is not the sole factor limiting needle decomposition in both
disturbed and rehabilitated forests. The positive effect was more sensitive to the N addition rate in the rehabilitated forest
than in the disturbed forest, however the reverse was true for the negative effect. These results suggest that nutrient status
could be one of the important factors in controlling the response of litter decomposition and its nutrient release to elevated
N deposition in reforested ecosystems in the study region. 相似文献
19.
Le Dinh Hung Kanji Hori Huynh Quang Nang Tran Kha Le Thi Hoa 《Journal of applied phycology》2009,21(3):265-272
The three color morphotypes of the red alga Kappaphycus alvarezii (brown, red and green) were cultured in Camranh Bay, Vietnam, using the fixed off-bottom monoline culture method to evaluate
the growth rate, carrageenan yield, 3,6-anhydrogalactose, gel strength and lectin content. The brown morphotype was cultivated
over a 12-month period; the red and green morphotypes were over a 6-month period. At the 60-day culture timepoint, the brown
morphotype showed a higher growth rate (3.5–4.6% day−1) from September to February, and lower growth rate (1.6–2.8% day−1) from March to August. Significant (P < 0.05) differences in growth rate between culture months were found with the brown morphotype. High growth rates for the
red (3.6–4.4% day−1) and green (3.7–4.2% day−1) morphotypes were obtained from September to February. The carrageenan yield, 3,6-anhydrogalactose and gel strength of the
three morphotypes showed little variation, with the highest values obtained in November–December. At the 30-day sampling point,
the brown morphotype had a higher lectin content (167–302 μg g−1 dry alga) from August to March and a lower lectin content (23–104 μg g−1 dry alga) from April to July. High lectin contents were recorded for the red (139–338 μg g−1 dry alga) and green (124–259 μg g−1 dry alga) morphotypes from September to February. This study shows that the different morphotypes of K. alvarezii can be grown in the tropical waters of the Camranh during the northeast monsoon, and part of the southwest monsoon, especially
the brown morphotype, which can be grown during any season. 相似文献
20.
Molecular characterization of phenylalanine ammonia lyase gene from <Emphasis Type="Italic">Cistanche deserticola</Emphasis> 总被引:1,自引:0,他引:1
Hu GS Jia JM Hur YJ Chung YS Lee JH Yun DJ Chung WS Yi GH Kim TH Kim DH 《Molecular biology reports》2011,38(6):3741-3750
We cloned the gene, CdPAL1, from Cistanche deserticola callus using RACE PCR with degenerate primers that were designed based on a multiple sequence alignment of known PAL genes
from other plant species. The gene shows high homology to other known PAL genes registered in GenBank. The recombinant protein
exhibited Michaelis–Menten kinetics with a K
m of 0.1013 mM, V
max of 4.858 μmol min−1, K
cat of 3.36 S−1, and K
cat/K
m is 33,168 M−1 S−1. The enzyme had an optimal pH of 8.5 and an activation energy of 38.92 kJ mol−1 when l-Phenylalanine was used as a substrate; l-tyrosine cannot be used as substrate for this protein. The optimal temperature was 55°C, and the thermal stability results
showed that, after a treatment at 70°C for 20 min, the protein retained 87% activity, while a treatment at 75°C for 20 min
resulted in a loss of over 85% of the enzyme activity. Treatment with heavy metal ions (Hg2+, Pb2+, and Zn2+) showed remarkable inhibitory effects. Among the intermediates from the lignin (cinnamyl alcohol, cinnamyl aldehyde, coniferyl
aldehyde, coniferyl alcohol), phenylpropanoid (cinnamic acid, coumaric acid, caffeic acid, and chlorogenic acid) and phenylethanoid
(tyrosol and salidroside) biosynthetic pathways, only cinnamic acid showed strong inhibitory effects against CdPAL1 activity with a K
i of 8 μM. Competitive inhibitor AIP exhibited potent inhibition with K
i = 0.056 μM. 相似文献