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1.
Functional groups of cytoplasmic pea β-glucosidase pretreated to an electrophoretically homogeneous state were identified.
Data on the pH dependence of the enzyme activity, calculated heat of ionization, photoinactivation of the enzyme in the presence
of methylene blue, and inactivation of the enzyme with diethyl pyrocarbonate suggest that the catalytic site of β-glucosidase
contains the carboxyl group of glutamic or aspartic acids and the imidazole group of histidine. 相似文献
2.
The effect of salinity and different nitrogen sources on the level of xanthine dehydrogenase (XDH) activity in roots and leaves
of pea plants was investigated. Two bands of xanthine dehydrogenase activity (XDH-R2, XDH-R3) were detected in roots after
native PAGE and staining with hypoxanthine as substrate. Only one band of XDH activity (XDH-L1) was detected in leaf extracts.
Within leaves of three different ages the highest XDH activity was detected in young leaves both under control as well as
stress conditions. Salinity did not affect significantly the activity of XDH in pea roots, however, depressed XDH activity
in leaves. A significant increase of XDH activity both in roots and leaves was observed only when ammonium was applied as
the sole N source. Increased concentration of ureides in the xylem sap of pea plants was observed for both ammonium and high
salt treatments, although the higher content of ureides in the xylem sap of 100 mM NaCl treated plants may be rather a result
of lower rate of exudation from roots than of increased root ureide biosynthesis. Thus, the changes of root and leaf XDH activity
in pea plants seem to be tightly correlated with ureide synthesis that is induced by NH
4
+
, the product of N fixation, and rather than by salinity. A contribution of pea XDH in increased oxygen species or uric acid
production under saline conditions seems to be less than likely. 相似文献
3.
Isoprene synthase (ISPS) catalyzes the elimination of pyrophosphate from dimethylallyl diphosphate (DMADP) forming isoprene,
a volatile hydrocarbon emitted from many plant species to the atmosphere. In the present work, immunological techniques were
applied to study and localize ISPS in poplar leaves (Populus × canescens). Immunogold labeling using polyclonal antibodies generated against His-tagged recombinant ISPS protein detected ca. 44%
of ISPS in the stroma of the chloroplasts and ca. 56% of gold particles attached to the stromal-facing side of the thylakoid
membranes. ISPS isolated from leaves exhibited the same biochemical properties as the recombinant ISPS without the plastid-targeting
peptide heterologous expressed in E. coli, whereas an additional C- or N-terminal His-tag changed the biochemical features of the recombinant enzyme with regard to
temperature, pH, and substrate dependence. In comparison to the closely related class of monoterpene synthases from angiosperms
and ISPS of oaks, the most striking feature of the poplar ISPS is a cooperative substrate dependence which is characteristic
to enzymes with positive substrate activation. The detection of four immunoreactive bands in poplar leaf extracts with isoelectric
points from 5.0 to 5.5 and a native molecular weight of ca. 51 kDa give reason for future studies on post-translational modifications
of ISPS. 相似文献
4.
Hubert J Dolecková-Maresová L Hýblová J Kudlíková I Stejskal V Mares M 《Experimental & applied acarology》2005,35(4):281-291
The stored-product mites are the most abundant and frequent group of pests living on the stored food products in Europe. They endanger public health since they produce allergens and transmit mycotoxin-producing fungi. Novel acaricidal compounds with inhibitory effects on the digestive enzymes of arthropods are a safe alternative to the traditional neurotoxic pesticides used for control of the stored-product pests. In this work, we explored the properties of acarbose, the low molecular weight inhibitor of -amylases (AI), as a novel acaricide candidate for protection of the stored products from infestation by Acarus siro (Acari: Acaridae). In vitro analysis revealed that AI blocked efficiently the enzymatic activity of digestive amylases of A. siro, and decreased the physiological capacity of mites gut in utilizing a starch component of grain flour. In vivo experiments showed that AI suppressed the population growth of A. siro. The mites were kept for three weeks on experimental diet enriched by AI in concentration range of 0.005 to 0.25%. Population growth of A. siro was negatively correlated with the content of AI in the treated diet with a half-population dose of 0.125%. The suppressive effect of AIs on stored-product mites is discussed in the context of their potential application in GMO crops 相似文献
5.
Lu Gan Xiaole Wang Zhijun Cheng Linglong Liu Jiulin Wang Zhe Zhang Yulong Ren Cailin Lei Zhichao Zhao Shanshan Zhu Qibing Lin Fuqing Wu Xiuping Guo Jie Wang Xin Zhang Jianmin Wan 《Plant cell reports》2016,35(8):1687-1698
Key message
WSL3 encodes β-ketoacyl-CoA reductase (KCR) in rice, in a similar way to YBR159w in yeast, and is essential for VLCFA biosynthesis and leaf wax accumulation.Abstract
Cuticular waxes on plant surfaces limit non-stomatal water loss, protect plants against deposits of dust and impose a physical barrier to pathogen infection. We identified a wax-deficient mutant of rice, wax crystal-sparse leaf 3 (wsl3), which exhibits a pleiotropic phenotype that includes reduced epicuticular wax crystals on the leaf surface and altered wax composition. Map-based cloning demonstrated that defects in the mutant were caused by two adjacent single-nucleotide changes in a gene encoding β-ketoacyl-CoA reductase (KCR) that catalyzes the second step of the fatty acid elongation reaction. The identity of WSL3 was further confirmed by genetic complementation. Transient assays of fluorescent protein-tagged WSL3 in tobacco protoplasts showed that WSL3 localizes to the endoplasmic reticulum, the compartment of fatty acid elongation in cells. Quantitative PCR and histochemical staining indicated that WSL3 is universally expressed in tissues. RNA interference of WSL3 caused a phenotype that mimicked the wsl3 mutant. Very long-chain fatty acids (VLCFAs) 20:0 and 22:0, or 20:1Δ11 and 22:1Δ13, were detected when WSL3 and Arabidopsis fatty acid elongation 1 (FAE1) were co-expressed in a yeast ybr159wΔ mutant strain. Our results indicated that WSL3 affects rice cuticular wax production by participating in VLCFA elongation.6.
7.
Abbandonato G Signore G Nifosì R Voliani V Bizzarri R Beltram F 《European biophysics journal : EBJ》2011,40(11):1205-1214
The photoswitching behaviour of the green fluorescent protein (GFP) chromophore and its analogs opens up exciting horizons
for the engineering and development of molecular devices for high sensitivity in vivo studies. In this work we present the
synthesis and photophysical study of four GFP chromophore analogs belonging to butenolide and pyrrolinone classes. These chromophores
possess an intriguing photoinduced cis–trans isomerization mechanism. Stereochemical structural assignment was unambiguously performed by 1D Nuclear Overhauser Effect
NMR measurements. The spectroscopic properties of both cis and trans isomers were studied, and photoconversion quantum yield for cis–trans isomerization was assessed to be in the 0.1–0.4 range. Finally, the 3JC,H coupling constant in the 13C–C=C–H motif was in excellent agreement with theoretical DFT calculations, thus providing a further confirmation of cis–trans photoisomerization of the structurally analog GFP chromophore. 相似文献
8.
D. P. Barik S. K. Naik A. Mudgal P. K. Chand 《In vitro cellular & developmental biology. Plant》2007,43(2):144-148
This study describes a reproducible protocol for rapid mass propagation of a multipurpose legume, Clitoria ternatea L., using cotyledonary node explants derived from axenic seedlings. Multiple shoots were induced in Murashige and Skoog (MS)
medium supplemented with N
6-benzyladenine (BA), zeatin riboside, or thidiazuron. N
6-Benzyladenine at 1.0 mg l−1 (4.44 μM) was most effective for shoot proliferation. Multiple shoots were also induced in nodal segments of in vitro-raised shoots grown on MS medium containing 1.0 mg l−1 (4.44 μM) of BA. Rooting was best induced in shoots grown on half-strength MS medium with 0.25 mg l−1 (1.42 μM) of indole-3-butyric acid. Plants were acclimatized in vermicompost and established in soil where they flowered
and formed mature seeds. 相似文献
9.
DeMason DA 《Planta》2005,222(1):151-166
A number of mutations that alter the form of the compound leaf in pea (Pisum sativum) has proven useful in elucidating the role that auxin might play in pea leaf development. The goals of this study were to determine if auxin application can rescue any of the pea leaf mutants and if gibberellic acid (GA) plays a role in leaf morphogenesis in pea. A tissue culture system was used to determine the effects of various auxins, GA or a GA biosynethesis inhibitor (paclobutrazol) on leaf development. The GA mutant, nana1 (na1) was analyzed. The uni-tac mutant was rescued by auxin and GA and rescue involved both a conversion of the terminal leaflet into a tendril and an addition of a pair of lateral tendrils. This rescue required the presence of cytokinin. The auxins tested varied in their effectiveness, although methyl-IAA worked best. The terminal tendrils of wildtype plantlets grown on paclobutrazol were converted into leaflets, stubs or were aborted. The number of lateral pinna pairs produced was reduced and leaf initiation was impaired. These abnormalities resembled those caused by auxin transport inhibitors and phenocopy the uni mutants. The na1 mutant shared some morphological features with the uni mutants; including, flowering late and producing leaves with fewer lateral pinna pairs. These results show that both auxin and GA play similar and significant roles in pea leaf development. Pea leaf morphogenesis might involve auxin regulation of GA biosynthesis and GA regulation of Uni expression. 相似文献
10.
Matías Maggi Natalia Damiani Sergio Ruffinengo David De Jong Judith Principal Martín Eguaras 《Experimental & applied acarology》2010,50(3):269-279
We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell
width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of
worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading
female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells. 相似文献
11.
The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed
in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under
control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially
in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of
the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically
active lipase from a basidiomycete fungus. 相似文献
12.
Maize is one of the more important agricultural crops in the world and, under certain conditions, prone to attack from pathogenic fungi. One of these, Aspergillus flavus, produces toxic and carcinogenic metabolites, called aflatoxins, as byproducts of its infection of maize kernels. The alpha-amylase of A. flavus is known to promote aflatoxin production in the endosperm of these infected kernels, and a 36-kDa protein from the Lablab purpureus, denoted AILP, has been shown to inhibit alpha-amylase production and the growth of A. flavus. Here, we report the isolation of six full-length labAI genes encoding AILP and a detailed analysis of the activities of the encoded proteins. Each of the six labAI genes encoded sequences of 274 amino acids, with the deduced amino acid sequences showing approximately 95-99% identity. The sequences are similar to those of lectin members of a legume lectin-arcelin-alpha-amylase inhibitor family reported to function in plant resistance to insect pests. The labAI genes did not show any of the structures characteristic of conserved structures identified in alpha-amylase inhibitors to date. The recombinant proteins of labAI-1 and labAI-2 agglutinated human red blood cells and inhibited A. flavus alpha-amylase in a manner similar to that shown by AILP. These data indicate that labAI genes are a new class of lectin members in legume seeds and that their proteins have both lectin and alpha-amylase inhibitor activity. These results are a valuable contribution to our knowledge of plant-pathogen interactions and will be applicable for developing protocols aimed at controlling A. flavus infection. 相似文献
13.
To facilitate molecular genetic studies of Streptomyces ambofaciens that produces spiramycin, a commercially important macrolide antibiotic used in human medicine against Gram-positive pathogenic
bacteria, the conditions for the conjugal transfer of DNA from E. coli to S. ambofaciens were established using a bacteriophage ϕC31 att/int system. The transconjugation efficiency of S. ambofaciens varied with the medium used; the highest frequency was obtained on AS-1 medium containing 10 mM MgCl2 without heat treatment of the spores. In addition, by cloning and sequencing the attB site, we identified that S. ambofaciens contains a single attB site within an ORF coding for a pirin homolog, and its attB site sequence shows 100% nt identity to the sequence of S. coelicolor and S. lividans, which have the highest efficiency in transconjugation using the ϕC31 att/int system. 相似文献
14.
Abdul Ghaffar Sher Afzal Khan Zahid Mukhtar Muhammad Ibrahim Rajoka Farooq Latif 《Molecular biology reports》2011,38(5):3227-3233
We studied heterologous expression of xylanase 11A gene of Chaetomium thermophilum in Pichia pastoris and characterized the thermostable nature of the purified gene product. For this purpose, the xylanase 11A gene of C. thermophilum was cloned in P. pastoris GS115 under the control of AOX1 promoter. The maximum extracellular activity of recombinant xylanase (xyn698: gene with intron) was 15.6 U ml−1 while that of recombinant without intron (xyn669) was 1.26 U ml−1 after 96 h growth. The gene product was purified apparently to homogeneity level. The optimum temperature of pure recombinant
xylanase activity was 70°C and the enzyme retained its 40.57% activity after incubation at 80°C for 10 min. It exhibited quite
lower demand of activation energy, enthalpy, Gibbs free energy, entropy, and xylan binding energy during substrate hydrolysis
than that required by that of the donor, thus indicating its thermostable nature. pH-dependent catalysis showed that it was
quite stable in a pH range of 5.5–8.5. This revealed that gene was successfully processed in P. pastoris and remained heat stable and may qualify for its potential use in paper and pulp and animal feed applications. 相似文献
15.
Root segments from seedlings of Panax ginseng produced adventitious roots directly when cultured on 1/2 MS solid medium lacking NH4NO3 and containing 3.0 mg l−1 IBA. Using this adventitious root formation, we developed rapid and efficient transgenic root formation directly from adventitious
root segments in P. ginseng. Root segments were co-cultivated with Agrobacterium tumefaciens (GV3101) caring β-glucuronidase (GUS) gene. Putative transgenic adventitious roots were formed directly from root segments on medium with 400 mg l−1 cefotaxime and 50 mg l−1 kanamycin. Kanamycin resistant adventitious roots were selected and proliferated as individual lines by subculturing on medium
with 300 mg l−1 cefotaxime and 50 mg l−1 kanamycin at two weeks subculture interval. Frequency of transient and stable expression of GUS gene was enhanced by acetosyringon (50 mg l−1) treatment. Integration of transgene into the plants was confirmed by the X-gluc reaction, PCR and Southern analysis. Production
of transgenic plants was achieved via somatic embryogenesis from the embryogenic callus derived from independent lines of
adventitious roots. The protocol for rapid induction of transgenic adventitious roots directly from adventitious roots can
be applied for a new Agrobacterium tumefaciens-mediated genetic transformation protocol in P. ginseng. 相似文献
16.
Dana Bernátová 《Biologia》2008,63(2):175-176
The paper brings information on an isolated occurrence and morphological characters of Carex × involuta and C. juncella populations in the Vel’ká Fatra Mts. Their presence has been known neither from the territory of Slovakia nor from the whole
Western Carpathians till now. 相似文献
17.
In pea, subtype H1-7 of histone H1 is specific for young actively growing tissues and disappears from chromatin of mature
tissues. We sequenced the alleles coding for three main variants, numbered according to the increase of the electrophoretic
mobility. Allele 1 differs from the most common allele 2 by eight nucleotide substitutions, two of them associated with amino
acid replacements, His->Tyr in the globular domain and Ala->Val in the C-terminal domain. Allele 3 differs from alleles 1
and 2 by a 24-bp deletion in the part coding for the C-terminal domain. In three greenhouse experiments, we compared quantitative
traits in nearly isogenic lines differing by these H1-7 variants. In experiment 1, three lines bearing either of the three
allelic variants were compared, the other experiments involved pairs of lines bearing variants 1 and 3. In all experiments,
statistically significant differences between the lines were registered, mostly related to the plant size. The most prominent
effect was associated with plant growth dynamics. Plants of line 3, carrying the 8-amino acid deletion in histone H1-7, on
average grew slower. In two experiments, the differences of the mean stem length persisted throughout plant growth while in
experiment 2 differences disappeared upon maturity. The H1-7 subtype is supposed to be related to maintenance of chromatin
state characteristic for cell growth and division. 相似文献
18.
G. J. Ma Q. J. Song S. G. Markell L. L. Qi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(7):1423-1432
Key message
A novel rust resistance gene, R 15 , derived from the cultivated sunflower HA-R8 was assigned to linkage group 8 of the sunflower genome using a genotyping-by-sequencing approach. SNP markers closely linked to R 15 were identified, facilitating marker-assisted selection of resistance genes.Abstract
The rust virulence gene is co-evolving with the resistance gene in sunflower, leading to the emergence of new physiologic pathotypes. This presents a continuous threat to the sunflower crop necessitating the development of resistant sunflower hybrids providing a more efficient, durable, and environmentally friendly host plant resistance. The inbred line HA-R8 carries a gene conferring resistance to all known races of the rust pathogen in North America and can be used as a broad-spectrum resistance resource. Based on phenotypic assessments of 140 F2 individuals derived from a cross of HA 89 with HA-R8, rust resistance in the population was found to be conferred by a single dominant gene (R 15 ) originating from HA-R8. Genotypic analysis with the currently available SSR markers failed to find any association between rust resistance and any markers. Therefore, we used genotyping-by-sequencing (GBS) analysis to achieve better genomic coverage. The GBS data showed that R 15 was located at the top end of linkage group (LG) 8. Saturation with 71 previously mapped SNP markers selected within this region further showed that it was located in a resistance gene cluster on LG8, and mapped to a 1.0-cM region between three co-segregating SNP makers SFW01920, SFW00128, and SFW05824 as well as the NSA_008457 SNP marker. These closely linked markers will facilitate marker-assisted selection and breeding in sunflower.19.
Tony Márcio Silva Fausto Bruno Dos Reis Almeida André Ricardo de Lima Damásio Alexandre Maller Michele Michelin João Atílio Jorge Ebert Seixas Hanna Maria Cristina Roque-Barreira Héctor F. Terenzi Maria de Lourdes Teixeira de Moraes Polizeli 《Biotechnology letters》2010,32(10):1449-1455
Treatment of Aspergillus niveus with 30 μg tunicamycin/ml did not interfere with α-glucosidase production, secretion, or its catalytic properties. Fully-
and under-glycosylated forms of the enzyme had similar molecular masses, ~56 kDa. Moreover, the absence of N-glycans did not affect either pH optimum (6.0) or temperature optimum (65°C). The Km and Vmax values of under- and fully-glycosylated forms of α-glucosidase were similar when assessed for hydrolysis of starch (~0.6 mg/ml,
~350 μmol glucose per min per ml), maltose (~0.54 μmol, ~330 μmol glucose per min per ml) and p-nitrophenyl-α-d-glucopyranoside (~0.54 μmol, ~8.28 μmol p-nitrophenol per min per ml). However, the under-glycosylated form was sensitive to high temperatures probably because, in
addition to stabilizing the protein conformation, glycosylation may also prevent unfolded or partially folded proteins from
aggregating. Binding assays clearly showed that the under-glycosylated protein did not bind to concanavalin A but has conserve
its jacalin-binding property, suggesting that only O-glycans might be intact on the tunicamycin treated form of the enzyme. 相似文献
20.
We identified diagnostic chloroplast DNA and mitochondrial DNA markers that can (a) discriminate between Larix gmelinii var. japonica and L. kaempferi, and (b) determine the maternal and paternal species of hybrids between them by exploiting the difference in inheritance
mode between the two genomes. We also investigated the hybridization rates at a site with two types of interspecific seed
orchard—a new type with rows of a single maternal clone of L. gmelinii var japonica among rows of L. kaemferi and a “traditional” type with multiple, intimately mixed clones—in 2 years using chloroplast diagnostic DNA markers. The
average hybridization rates in the single maternal clone (SMC) interspecific seed orchards [84.2% (±9.4%) in 2004 and 94.1%
(±3.9%) in 2005) were higher than that in the traditional interspecific seed orchards [15.9% (±13.4%) in 2004 and 30.0% (±25.5%)
in 2005] because of the self-incompatibility of the L. gmelinii var. japonica clone. We detected significant differences in hybridization rates between the orchard types in both investigated years (P < 0.001, analysis of variance, ANOVA). This finding suggests that SMC interspecific seed orchards can reliably provide seeds
with high proportions of hybrids. In the traditional interspecific seed orchard, there were significant differences in the
proportions of hybrids among L. gmelinii var. japonica seeds between the two years (P < 0.005, ANOVA), which may have been partly due to differences in the relative amounts of pollen cones produced by L. gmelinii var. japonica and L. kaempferi. 相似文献