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1.
Fitoterapia ; 162: 105292, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36064153

ABSTRACT

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated ß-D-fucopyranosyl and ß-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 µM. Structure-activity relationships of the isolated compounds are discussed.


Subject(s)
Rosales , Sesquiterpenes , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Glycosides/pharmacology , Lipopolysaccharides/pharmacology , Molecular Structure , Nitric Oxide/metabolism , Plant Extracts/chemistry , Rosales/metabolism , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology
2.
Plant Cell ; 32(6): 1868-1885, 2020 06.
Article in English | MEDLINE | ID: mdl-32276984

ABSTRACT

Some plants fix atmospheric nitrogen by hosting symbiotic diazotrophic rhizobia or Frankia bacteria in root organs known as nodules. Such nodule symbiosis occurs in 10 plant lineages in four taxonomic orders: Fabales, Fagales, Cucurbitales, and Rosales, which are collectively known as the nitrogen-fixing clade. Nodules are divided into two types based on differences in ontogeny and histology: legume-type and actinorhizal-type nodules. The evolutionary relationship between these nodule types has been a long-standing enigma for molecular and evolutionary biologists. Recent phylogenomic studies on nodulating and nonnodulating species in the nitrogen-fixing clade indicated that the nodulation trait has a shared evolutionary origin in all 10 lineages. However, this hypothesis faces a conundrum in that legume-type and actinorhizal-type nodules have been regarded as fundamentally different. Here, we analyzed the actinorhizal-type nodules formed by Parasponia andersonii (Rosales) and Alnus glutinosa (Fagales) and found that their ontogeny is more similar to that of legume-type nodules (Fabales) than generally assumed. We also show that in Medicago truncatula, a homeotic mutation in the co-transcriptional regulator gene NODULE ROOT1 (MtNOOT1) converts legume-type nodules into actinorhizal-type nodules. These experimental findings suggest that the two nodule types have a shared evolutionary origin.


Subject(s)
Fagales/metabolism , Fagales/microbiology , Medicago truncatula/microbiology , Mutation/genetics , Nitrogen Fixation/genetics , Nitrogen Fixation/physiology , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Root Nodulation/genetics , Plant Root Nodulation/physiology , Root Nodules, Plant/metabolism , Root Nodules, Plant/physiology , Rosales/metabolism , Rosales/microbiology
3.
IET Syst Biol ; 12(6): 289-293, 2018 12.
Article in English | MEDLINE | ID: mdl-30472693

ABSTRACT

Green houses play a vital role in modern agriculture. Artificial light illumination is very important in a green house. While light is necessary for plant growth, excessive light in a green house may not bring more profit and even damages plants. Developing a plant-physiology-based light control strategy in a green house is important, which implies that a state-space model on photosynthetic activities is very useful because modern control theories and techniques are usually developed according to model structures in the state space. In this work, a simplified model structure on photosystem II activities was developed with seven state variables and chlorophyll fluorescence (ChlF) as the observable variable. Experiments on ChlF were performed. The Levenberg-Marquardt algorithm was used to estimate model parameters from experimental data. The model structure can fit experimental data with a small relative error (<2%). ChlF under different light intensities were simulated to show the effect of light intensity on ChlF emission. A simplified model structure with fewer state variables and model parameters will be more robust to perturbations and model parameter estimation. The model structure is thus expected useful in future green-house light control strategy development.


Subject(s)
Chlorophyll/metabolism , Darkness , Fluorescence , Models, Biological , Photosystem II Protein Complex/metabolism , Adenosine Triphosphate/metabolism , Camellia/metabolism , Camellia/radiation effects , Rosales/metabolism , Rosales/radiation effects
4.
Ann Bot ; 120(6): 967-977, 2017 Nov 28.
Article in English | MEDLINE | ID: mdl-28961748

ABSTRACT

BACKGROUND AND AIMS: Tapiscia sinensis (Tapisciaceae) is a functional androdioecious species with both male and hermaphroditic individuals, and fruit ripening overlaps with flowering in the hermaphroditic individuals. Pollen vitality was lower in the hermaphrodites than in the males. Anther development requires nutrients, and carbohydrates are the basic nutrients; abnormal carbohydrate metabolism will result in pollen abortion. The aim of this research was to gain insight into the relationship between carbohydrate metabolism and the weakening of the male function of hermaphroditic flowers in T. sinensis. METHODS: Observation of morphology and microscopic and sub-microscopic structures was carried out. Sugar measurements and quantitative real-time PCR analysis were performed for the genes related to sugar metabolism and transport in the development of anthers in both males and hermaphrodites. The expression pattern of Cell wall invertase 2 (CWI2) and Sucrose transporter 2 (ST2) was explored by in situ hybridization. KEY RESULTS: At the vacuolate microspore (VM) stage, polysaccharides accumulated in the connective tissue of the hermaphroditic anthers, and the levels of total soluble sugar, sucrose and starch in the hermaphroditic anthers were significantly lower than in the male anthers. Most of the hermaphroditic pollen grains were empty, with degradation of the cytoplasm, absence of an intine layer and defective exines. There was a significant differential expression between male and hermaphroditic flowers of several key genes that are involved in sugar metabolism, transport and intine development. CWI2 and ST2 were expressed in the tapetum and microspores. The expression of CWI2 was significantly lower in hermaphrodites than in the males. CONCLUSIONS: Fruit ripening overlaps with flowering, leading to a severe reproductive burden on the hermaphroditic individuals. The hermaphroditic flowers regulating carbohydrate metabolism and transport to affect resources are biased towards the female function to ensure reproduction, causing a deficiency in resources for the development of pollen; thus, the pollen viability is lower. This makes it easier for males to invade the hermaphroditic population and form a functional androdioecious breeding system.


Subject(s)
Carbohydrate Metabolism , Flowers/growth & development , Gene Expression Regulation, Plant , Rosales/genetics , Rosales/metabolism , Flowers/genetics , Flowers/metabolism , Hermaphroditic Organisms , Plant Proteins/genetics , Plant Proteins/metabolism , Rosales/growth & development , Trees/genetics , Trees/growth & development , Trees/metabolism
5.
Plant Physiol Biochem ; 105: 310-320, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27336837

ABSTRACT

Seaweed extracts (SWE) might play an important role in enhancing growth and phytochemical composition of medicinal shrubs. In this study, we investigate the morphological, physiological and biochemical effects of irrigation levels (100% and 50% of the evapotranspiration rate) coupled with a weekly treatment of SWE of Ascophyllum nodosum at 5 and 7 mL L(-1) as a soil drench or foliar spray on Spiraea nipponica "Snowmound" and Pittosporum eugenioides "Variegatum" grown in containers under controlled greenhouse conditions. In addition, the phenolic and flavonoid content, antioxidant capacity and lipid peroxidation in both plant species was largely enhanced while the proline accumulation was reduced. After 8 weeks of treatments, drought condition reduced plant vegetative growth and gas exchange, as well as leaf water potential, but increased the phenolic and flavonoid contents in leaves, their antioxidant capacities and proline content. The application of SWE enhanced the performance of both species during mild drought conditions by means of increasing leaf number and area, dry weights, plant height, gas exchange and leaf water potential. The maximum vegetative growth, physiological performance and phytochemical composition of both species was achieved using the drench SWE treatments (5 and 7 mL L(-1)) in moderate drought conditions, which improved the plant water status, stomatal conductance, and photosynthetic rate. SWE enhanced plant growth and the phytochemical composition and antioxidant capacity of plant leaves of both species during moderate drought conditions.


Subject(s)
Antioxidants/analysis , Phytochemicals/analysis , Quantitative Trait, Heritable , Rosales/growth & development , Seaweed/chemistry , Spiraea/growth & development , Stress, Physiological , Analysis of Variance , Biomass , Lipid Peroxidation , Plant Leaves/anatomy & histology , Proline/metabolism , Rosales/anatomy & histology , Rosales/metabolism , Spiraea/anatomy & histology , Spiraea/metabolism , Water
6.
Biochemistry ; 49(19): 4085-93, 2010 May 18.
Article in English | MEDLINE | ID: mdl-20377207

ABSTRACT

All plants contain hemoglobins that fall into distinct phylogenetic classes. The subset of plants that carry out symbiotic nitrogen fixation expresses hemoglobins that scavenge and transport oxygen to bacterial symbiotes within root nodules. These "symbiotic" oxygen transport hemoglobins are distinct in structure and function from the nonoxygen transport ("nonsymbiotic") Hbs found in all plants. Hemoglobins found in two closely related plants present a paradox concerning hemoglobin structure and function. Parasponia andersonii is a nitrogen-fixing plant that expresses a symbiotic hemoglobin (ParaHb) characteristic of oxygen transport hemoglobins in having a pentacoordinate ferrous heme iron, moderate oxygen affinity, and a relatively rapid oxygen dissociation rate constant. A close relative that does not fix nitrogen, Trema tomentosa, expresses hemoglobin (TremaHb) sharing 93% amino acid identity to ParaHb, but its phylogeny predicts a typical nonsymbiotic hemoglobin with a hexacoordinate heme iron, high oxygen affinity, and slow oxygen dissociation rate constant. Here we characterize heme coordination and oxygen binding in TremaHb and ParaHb to investigate whether or not two hemoglobins with such high sequence similarity are actually so different in functional behavior. Our results indicate that the two proteins resemble nonsymbiotic hemoglobins in the ferric oxidation state and symbiotic hemoglobins in the ferrous oxidation state. They differ from each other only in oxygen affinity and oxygen dissociation rate constants, two factors key to their different functions. These results demonstrate distinct mechanisms for convergent evolution of oxygen transport in different phylogenetic classes of plant hemoglobins.


Subject(s)
Biological Evolution , Hemoglobins/chemistry , Plant Proteins/metabolism , Rosales/metabolism , Trema/metabolism , Amino Acid Sequence , Binding Sites , Hemoglobins/genetics , Molecular Sequence Data , Nitrogen/metabolism , Oxygen/metabolism , Phylogeny , Plant Proteins/genetics , Rosales/genetics , Symbiosis , Trema/genetics
7.
Chemosphere ; 59(8): 1161-8, 2005 May.
Article in English | MEDLINE | ID: mdl-15833490

ABSTRACT

The purpose of this study is to investigate the bio-accumulation of Cd(II), Cu(II), Pb(II) and Zn(II) in Pittosporum tobira (Thunb.) Aiton leaves sampled in different zones of Messina, in order to assess the level of atmospheric metal deposition in correlation with the traffic volume. Derivative stripping chronopotentiometry was used as a practical, precise and sensitive technique to determine simultaneously Cd, Cu, Pb and Zn levels in Pittosporum leaves. In the optimised electro-chemical conditions, detection limits lower than 0.05 microg kg(-1) were achieved, whereas the accuracy, expressed as obtained recoveries from certified materials, was in the range 93.5-102.7%. The obtained data provided evidence that Cd and Pb levels significantly decreased from high to low traffic density zones (p < 0.005, ANOVA), whereas Cu and Zn are accumulated by plants particularly from the soil and their contents is not related to the traffic volume.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring/statistics & numerical data , Metals, Heavy/analysis , Plant Leaves/metabolism , Rosales/metabolism , Analysis of Variance , Environmental Monitoring/methods , Italy , Metals, Heavy/pharmacokinetics , Potentiometry/methods , Spectrophotometry, Atomic , Vehicle Emissions/analysis
8.
Plant J ; 28(3): 319-32, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11722774

ABSTRACT

Fruit ripening is characterized by dramatic changes in gene expression, enzymatic activities and metabolism. Although the process of ripening has been studied extensively, we still lack valuable information on how the numerous metabolic pathways are regulated and co-ordinated. In this paper we describe the characterization of FaMYB1, a ripening regulated strawberry gene member of the MYB family of transcription factors. Flowers of transgenic tobacco lines overexpressing FaMYB1 showed a severe reduction in pigmentation. A reduction in the level of cyanidin 3-rutinoside (an anthocyanin) and of quercetin-glycosides (flavonols) was observed. Expression of late flavonoid biosynthesis genes and their enzyme activities were adversely affected by FaMYB1 overexpression. Two-hybrid assays in yeast showed that FaMYB1 could interact with other known anthocyanin regulators, but it does not act as a transcriptional activator. Interestingly, the C-terminus of FaMYB1 contains the motif pdLNL(D)/(E)Lxi(G)/S. This motif is contained in a region recently proposed to be involved in the repression of transcription by AtMYB4, an Arabidopsis MYB protein. Our results suggest that FaMYB1 may play a key role in regulating the biosynthesis of anthocyanins and flavonols in strawberry. It may act to repress transcription in order to balance the levels of anthocyanin pigments produced at the latter stages of strawberry fruit maturation, and/or to regulate metabolite levels in various branches of the flavonoid biosynthetic pathway.


Subject(s)
Anthocyanins/biosynthesis , Flavonoids/biosynthesis , Nicotiana/genetics , Proto-Oncogene Proteins c-myb , Rosales/metabolism , Amino Acid Sequence , Anthocyanins/genetics , Arabidopsis Proteins , DNA-Binding Proteins , Flavonols , Fruit/enzymology , Fruit/genetics , Fruit/growth & development , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Molecular Sequence Data , Pigmentation/genetics , Pigmentation/physiology , Plant Proteins , Rosales/enzymology , Sequence Homology, Amino Acid , Transcription, Genetic
9.
Plant Physiol ; 127(1): 230-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11553751

ABSTRACT

In raspberry (Rubus idaeus), development of fruit color and flavor are critically dependent on products of the phenylpropanoid pathway. To determine how these metabolic functions are integrated with the fruit ripening program, we are examining the properties and expression of key genes in the pathway. Here, we report that L- phenylalanine ammonia-lyase (PAL) is encoded in raspberry by a family of two genes (RiPAL1 and RiPAL2). RiPAL1 shares 88% amino acid sequence similarity to RiPAL2, but phylogenetic analysis places RiPAL1 and RiPAL2 in different clusters within the plant PAL gene family. The spatial and temporal expression patterns of the two genes were investigated in various vegetative and floral tissues using the reverse transcriptase competitor polymerase chain reaction assay. Although expression of both genes was detected in all tissues examined, RiPAL1 was associated with early fruit ripening events, whereas expression of RiPAL2 correlated more with later stages of flower and fruit development. Determination of the absolute levels of the two transcripts in various tissues showed that RiPAL1 transcripts were 3- to 10-fold more abundant than those of RiPAL2 in leaves, shoots, roots, young fruits, and ripe fruits. The two RiPAL genes therefore appear to be controlled by different regulatory mechanisms.


Subject(s)
Coenzyme A Ligases/genetics , Phenylalanine Ammonia-Lyase/genetics , Rosales/genetics , Acyltransferases/genetics , Acyltransferases/metabolism , Cloning, Molecular , Coenzyme A Ligases/metabolism , DNA, Complementary , DNA, Plant , Evolution, Molecular , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Multigene Family , Phenylalanine Ammonia-Lyase/classification , Phylogeny , Plant Structures/genetics , Plant Structures/metabolism , Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Rosales/metabolism
10.
Plant J ; 27(4): 315-24, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11532177

ABSTRACT

Petunia hybrida W115 was transformed with a Clarkia breweri S-linalool synthase cDNA (lis). Lis was expressed in all tissues analysed, and linalool was detected in leaves, sepals, corolla, stem and ovary, but not in nectaries, roots, pollen and style. However, the S-linalool produced by the plant in the various tissues is not present as free linalool, but was efficiently converted to non-volatile S-linalyl-beta-D-glucopyranoside by the action of endogenous glucosyltransferase. The results presented demonstrate that monoterpene production can be altered by genetic modification, and that the compounds produced can be converted by endogenous enzymatic activity.


Subject(s)
Glucosides/metabolism , Monoterpenes , Rosales/enzymology , Terpenes/metabolism , Acyclic Monoterpenes , Chromatography, Liquid , DNA, Complementary , Hydro-Lyases/genetics , Hydro-Lyases/metabolism , Mass Spectrometry , Molecular Sequence Data , Plant Leaves/enzymology , Plant Leaves/genetics , Plant Leaves/metabolism , Plants, Genetically Modified/enzymology , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Rosales/genetics , Rosales/metabolism
11.
J Food Prot ; 64(9): 1425-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11563522

ABSTRACT

The efficacy of sucrose combined with CaCl2 during osmotic dehydration (OD) was tested for the control of Botrytis cinerea, Colletotrichum acutatum, and Penicillium expansum growth on lightly processed apple slices. The objective of this work was to determine whether the addition of CaCl2 in the osmotic solutions would limit the proliferation of fungal decay organisms. Slices were submitted to OD for 1 h at 25 degrees C in solutions containing 5 to 65% sucrose. Calcium chloride was added to a similar set of sucrose solutions at 0 to 8%. Control slices were made of untreated slices, and slices were processed in water. The mass ratio of the slices did not vary when fruit pieces were processed in solutions containing 5 to 65% sucrose. These slices showed a high susceptibility to spoilage compared to the control slices not submitted to OD: a significant twofold and 60% increase in decay area caused by B. cinerea and P. expansum, respectively, was observed when slices were processed in 50% sucrose/0% CaCl2; C. acutatum showed a significant 50% increase in decay area when slices were processed in 20% sucrose/0% CaCl2. Calcium uptake was significantly increased when slices were processed in CaCl2 solutions, and the highest Ca content was observed when processed in 8% CaCl2, reaching 40 times that of the control slices processed in water. Calcium-treated slices were less susceptible to spoilage by all three pathogens, and the most effective combination in reducing apple slice spoilage was 20 to 30% sucrose combined with 2% CaCl2.


Subject(s)
Calcium Chloride/pharmacology , Food Preservation/methods , Fungi/drug effects , Rosales/metabolism , Sucrose/pharmacology , Dehydration , Osmosis , Solutions , Treatment Outcome
12.
Planta ; 212(4): 619-26, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11525520

ABSTRACT

Vegetative-bud dormancy in peach (Prunus persica L. Batsch) trees is known to be correlated, at least partially, with properties of the underlying bud tissues during winter. Variations in the activity and amount of plasma-membrane H -ATPase were observed. A full-length cDNA, PPA2 (Prunus persica H+-ATPase 2) and three partial cDNAs (PPA1, PPA3 and PPA4) for the plasma-membrane H+-ATPase from peach trees were isolated by reverse transcription (RT)-coupled rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR). The accumulation of plasma membrane H+-ATPase transcripts was then studied in vegetative buds during dormancy and breaking of dormancy. Competitive RT-PCR analysis revealed that, during dormancy, the plasma membrane H+-ATPase transcripts were higher in the tissues underlying the buds than in the buds themselves. After dormancy release, the level of PPA1, 2, 3 mRNA increased, whereas the level of PPA4 decreased in the buds. When trees were kept in a greenhouse (i.e. sheltered from chilling), no accumulation of PPA mRNA could be detected. These results suggest that there is a differential accumulation of H+-ATPase mRNA between the bud and the underlying bud tissues during dormancy, and that chilling could act as a decisive factor.


Subject(s)
Proton-Translocating ATPases/genetics , Rosales/genetics , Trees/genetics , Base Sequence , Chronobiology Phenomena , DNA, Plant , Gene Expression Regulation, Plant , Molecular Sequence Data , Multigene Family , Plant Stems/genetics , Plant Stems/metabolism , Proton-Translocating ATPases/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Rosales/metabolism , Trees/metabolism
13.
Plant Physiol ; 126(4): 1588-97, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11500557

ABSTRACT

We have shown that two 27-kD proteins, designated as WAP27A and WAP27B, were abundantly accumulated in endoplasmic reticulum-enriched fractions isolated from cortical parenchyma cells of mulberry tree (Morus bombycis Koidz.) during winter (N. Ukaji, C. Kuwabara, D. Takezawa, K. Arakawa, S. Yoshida, S. Fujikawa [1999] Plant Physiol 120: 480--489). In the present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in mulberry tree during winter.


Subject(s)
Endoplasmic Reticulum/metabolism , Heat-Shock Proteins/isolation & purification , Plant Proteins/isolation & purification , Rosales/metabolism , Trees/metabolism , Acclimatization , Amino Acid Sequence , Cold Climate , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism , Molecular Sequence Data , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Structures , RNA, Messenger/metabolism , RNA, Plant/metabolism , Rosales/cytology , Rosales/genetics , Seasons , Sequence Homology, Amino Acid , Trees/cytology , Trees/genetics
14.
Shokuhin Eiseigaku Zasshi ; 42(2): 144-7, 2001 Apr.
Article in Japanese | MEDLINE | ID: mdl-11486382

ABSTRACT

The antigenicity and phototoxicity of water-soluble extract from Salacia reticulata (SRE) were examined in guinea pigs. In a study of active systemic anaphylaxis reaction, neither the oral administration group (64 or 320 mg/kg, 5 times/week, 3 weeks) nor the subcutaneous administration group (64 mg/kg, 1 time/week, 3 weeks) exhibited any anaphylactic reaction. Moreover, sensitization with serum obtained from these animals did not induce passive cutaneous anaphylaxis reaction in normal animals. In a phototoxicity study, oral administration of SRE (320 mg/kg) induced neither erythema nor edema. These results suggest that SRE is not antigenic or phototoxic.


Subject(s)
Anaphylaxis/immunology , Dermatitis, Phototoxic/immunology , Plants, Medicinal/chemistry , Rosales/metabolism , Animals , Epitopes , Guinea Pigs , Male , Plant Extracts/immunology , Plant Extracts/toxicity , Solubility , Water
15.
J Exp Bot ; 52(362): 1769-77, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11520865

ABSTRACT

The influence of the O(2) and CO(2) concentration and the temperature on the O(2) uptake rate of cool-stored intact pears and pear cell protoplasts in suspension was compared. Protocols to isolate pear cell protoplasts from pear tissue and two methods to measure protoplast respiration have been developed. Modified Michaelis-Menten kinetics were applied to describe the effect of the O(2) and the CO(2) concentration on the O(2) uptake rate and temperature dependence was analysed with an Arrhenius equation. Both systems were described with a non-competitive type of CO(2) inhibition. Due to the inclusion of gas diffusion properties, the Michaelis-Menten constant for intact pears (2.5 mM) was significantly larger than the one for protoplasts in suspension (3 microM), which was in turn larger than the Michaelis-Menten constant obtained in mitochondrial respiration measurements described in the literature. It was calculated that only 3.6% of the total diffusion effect absorbed in the Michaelis-Menten constant for intact pears, could be attributed to intracellular gas diffusion. The number of cells per volume of tissue was counted microscopically to establish a relationship between the pear cell protoplast and intact pear O(2) uptake rate. A remarkable similarity was observed: values of 61.8 nmol kg(-1) s(-1) for protoplasts and 87.1 nmol kg(-1) s(-1) for intact pears were obtained. Also, the inhibitory effect of CO(2) on the respiration rate was almost identical for protoplasts and intact pears, suggesting that protoplast suspensions are useful for the study of other aspects of the respiration metabolism.


Subject(s)
Rosales/metabolism , Carbon Dioxide/metabolism , Cell Respiration , Cell Survival , Fruit/metabolism , Kinetics , Models, Biological , Oxygen/metabolism , Oxygen Consumption , Protoplasts/metabolism , Temperature
16.
J Exp Bot ; 52(362): 1949-51, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11520885

ABSTRACT

The nucleotide sequences of eight cDNAs encoding putative aquaporins obtained from a leaf Vitis hybrid Richter-110 cDNA library are reported. They encode proteins ranging from 249 to 287 amino acids with characteristic sequences that clearly include them within the MIP family. According to available database sequence homologies, they can be classified into four groups belonging to two subfamilies: PIP (PIP1 and PIP2) and TIP (gamma-TIP and delta-TIP). In order to elucidate the expression patterns of these putative aquaporins in the plant, specific probes were developed and tissue specific differential expression was tested by reverse Northern and compared with two reference genes (malic enzyme and glutamate dehydrogenase). Clearly, most of the putative aquaporins had higher expression in roots, whereas expression in shoot and leaves was generally weaker than the reference genes.


Subject(s)
Aquaporins/genetics , Arabidopsis Proteins , Plant Proteins/genetics , Rosales/genetics , Aquaporins/metabolism , Arabidopsis/genetics , Arabidopsis/metabolism , DNA, Complementary , DNA, Plant , Gene Expression Regulation, Plant , Glutamate Dehydrogenase/genetics , Ion Channels/genetics , Ion Channels/metabolism , Molecular Sequence Data , Plant Proteins/metabolism , Plant Structures/genetics , Plant Structures/metabolism , Rosales/metabolism , Sequence Homology, Amino Acid
17.
J Exp Bot ; 52(361): 1665-71, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11479331

ABSTRACT

Nitrogen is remobilized from storage for the growth of Malus domestica leaves each spring. Seasonal patterns of N translocation in the xylem sap as a consequence of remobilization were determined in 2-year-old 'Golden delicious' trees grafted on M9 rootstocks. The trees were grown in sand culture and (15)NH(4)(15)NO(3) at 10.4 atom% abundance supplied during August-September. The following year no further N was supplied and destructive harvests were taken during bud burst and leaf growth to determine the patterns of N remobilization together with the isolation of xylem sap for an analysis of their amino acid profiles and (15)N enrichments by GC-MS. The concentration of amino acids in the xylem sap rose following bud burst, peaked at full bloom and then fell again during petal fall and fruit set. The peak in amino acid concentration corresponded with the period when the rate of N remobilization was the fastest. The majority of labelled N was recovered in Asn, Gln + Glu and Asp demonstrating that they were being translocated as a consequence of remobilization. In a second experiment, 8-year-old trees growing in an orchard were fertilized with N either in the autumn or spring. Xylem sap samples were collected in the spring and early summer and, by comparison with the amino acid profiles recovered in trees from both treatments, Asn was identified as the main compound translocated as a consequence of both remobilization and root uptake of N, although there was evidence that root uptake of N occurred later. The data are discussed in relation to quantifying the internal cycling of N in trees.


Subject(s)
Amino Acids/metabolism , Nitrogen/metabolism , Plant Roots/metabolism , Rosales/metabolism , Biological Transport , Fruit/growth & development , Fruit/metabolism , Isotope Labeling , Nitrates/pharmacology , Nitrogen/pharmacology , Plant Shoots/drug effects , Plant Shoots/growth & development , Plant Shoots/metabolism , Quaternary Ammonium Compounds/pharmacology , Reproduction , Rosales/drug effects , Seasons , Trees/growth & development , Trees/metabolism
18.
Glycobiology ; 11(8): 621-32, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11479273

ABSTRACT

We report the characterization of two Chinese hamster ovary cell lines that produce large amounts of sulfated N-linked oligosaccharides. Clones 26 and 489 were derived by stable transfection of the glycosaminoglycan-deficient cell mutant pgsA-745 with a cDNA library prepared from wild-type cells. Peptide:N-glycanase F released nearly all of the sulfate label, indicating that sulfation had occurred selectively on the Asn-linked glycans. Hydrazinolysis followed by nitrous acid treatment at pH 4 and borohydride reduction yielded reduced sulfated disaccharides that comigrated with standard Gal3SO4beta1-4anhydromannitol. The disaccharides were resistant to periodate oxidation but became sensitive after the sulfate group was removed by methanolysis, indicating that the sulfate was located at C3 of the galactose residues. Maackia amurensis lectin bound to the sulfated glycopeptides on the cell surface and in free form, even after sialidase treatment. This finding indicates that the lectin requires only a charged group at C3 of the galactose unit and not an intact sialic acid. Growth of cells with chlorate restored sialidase sensitivity to lectin binding, indicating that sulfation and sialylation occurred largely at the same sites. The enhanced sulfation was due to elevated sulfotransferase activity that catalyzed transfer of sulfate from phosphoadenosine-5'-phosphosulfate to Galbeta1-4(3)GlcNAcbeta-O-naphthalenemethanol.


Subject(s)
Asparagine/metabolism , Galactose/metabolism , Phytohemagglutinins/metabolism , Polysaccharides/metabolism , Animals , CHO Cells , Carbohydrate Conformation , Cell Line , Cricetinae , Macromolecular Substances , Plant Lectins , Rosales/enzymology , Rosales/metabolism , Sulfates/metabolism , Sulfotransferases/metabolism , Transfection
19.
J Cell Biol ; 154(5): 973-82, 2001 Sep 03.
Article in English | MEDLINE | ID: mdl-11524437

ABSTRACT

alpha-Amylase is expressed in cotyledons of germinated Vigna mungo seeds and is responsible for the degradation of starch that is stored in the starch granule (SG). Immunocytochemical analysis of the cotyledon cells with anti-alpha-amylase antibody showed that alpha-amylase is transported to protein storage vacuole (PSV) and lytic vacuole (LV), which is converted from PSV by hydrolysis of storage proteins. To observe the insertion/degradation processes of SG into/in the inside of vacuoles, ultrastructural analyses of the cotyledon cells were conducted. The results revealed that SG is inserted into LV through autophagic function of LV and subsequently degraded by vacuolar alpha-amylase. The autophagy for SG was structurally similar to micropexophagy detected in yeast cells. In addition to the autophagic process for SG, autophagosome-mediated autophagy for cytoplasm and mitochondria was detected in the cotyledon cells. When the embryo axes were removed from seeds and the detached cotyledons were incubated, the autophagosome-mediated autophagy was observed, but the autophagic process for the degradation of SG was not detected, suggesting that these two autophagic processes were mediated by different cellular mechanisms. The two distinct autophagic processes were thought to be involved in the breakdown of SG and cell components in the cells of germinated cotyledon.


Subject(s)
Autophagy/physiology , Cotyledon/metabolism , Rosales/metabolism , Starch/metabolism , Cell Fractionation , Cotyledon/ultrastructure , Cytoplasmic Granules/metabolism , Immunohistochemistry , Microscopy, Confocal , Models, Biological , alpha-Amylases/metabolism
20.
J Agric Food Chem ; 49(7): 3164-8, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11453747

ABSTRACT

Lower antioxidant activity in white wines in comparison to red wines lies in the low grape-skin-derived polyphenol content. This paper reports the analysis of the antioxidant capacities of white wine samples obtained along two different processing procedures directed to enrich the wine with polyphenols. White wine samples derived from whole squeezed grapes stored for increasing periods of time (up to 18 h) contained increasing concentrations of polyphenols (from 0.35 to 0.55 mmol/L) and, in parallel, exhibited increased capacity to scavenge free radicals and to inhibit copper ion-induced low-density lipoprotein (LDL) oxidation. However, addition of increasing concentrations of alcohol (up to 18%) to the whole squeezed grapes remarkably augmented the extraction of grape skin polyphenols into the wine up to 1.25 mmol/L, resulting in an increased capacity of the wine to scavenge free radicals and to inhibit LDL oxidation, to an extent similar to that of red wine. The extent of LDL oxidation inhibition was directly related to the wine polyphenolic content (r = 0.986). It is concluded that processing white wine by imposing a short period of grape skin contact in the presence of alcohol leads to extraction of grape skin polyphenols and produces polyphenol-rich white wine with antioxidant characteristics similar to those of red wine.


Subject(s)
Flavonoids , Phenols/isolation & purification , Polymers/isolation & purification , Rosales/chemistry , Wine/analysis , Antioxidants , Food Handling , Free Radical Scavengers , Lipoproteins, LDL/metabolism , Oxidation-Reduction , Polyphenols , Rosales/metabolism
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