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PubMed1997

A homolog of the Arabidopsis thaliana ERS gene is actively regulated in Rumex palustris upon flooding.

A cDNA homologous to the ethylene-response sensors (ERS/ETR1) from Arabidopsis thaliana was isolated from a Rumex palustris cDNA library. This cDNA, RP-ERS1, was 2421 bp long and shared 66% nucleotide homology with ETR1 and ERS in their coding regions. The transcript level of RP-ERS1 was actively regulated during the leafelongation response of R. palustris upon flooding. RP-ERS1 transcript levels increased after submergence, and also after exposure to high concentrations of ethylene and carbon dioxide and low concentrations of oxygen. These results suggest that R. palustris plants may respond to flooding stress by increasing the number of their ethylene receptors.

Amino Acid Sequence↗
PubMed2002

1,5-dihydroxyanthraquinones and an anthrone from roots of Rumex crispus.

From the roots of Rumex crispus, two known anthraquinones and a new one together with a new anthrone were isolated and the structures of compounds 1-4 were elucidated by spectroscopic means. The singlet oxygen generation capacity was tested with 1,3-diphenylisobenzofuran (DPBF) for compounds 1-4.

Algorithms↗
PubMed2002

Submergence research using Rumex palustris as a model; looking back and going forward.

Flooding is a phenomenon that destroys many crops worldwide. During evolution several plant species evolved specialized mechanisms to survive short- or long-term waterlogging and even complete submergence. One of the plant species that evolved such a mechanism is Rumex palustris. When flooded, this plant species is capable to elongate its petioles to reach the surface of the water. Thereby it restores normal gas exchange which leads to a better survival rate. Enhanced levels of ethylene, due to physical entrapment, is the key signal for the plant that its environment has changed from air to water. Subsequently, a signal transduction cascade involving at least four (classical) plant hormones, ethylene, auxin, abscisic acid, and gibberellic acid, is activated. This results in hyponastic growth of the leaves accompanied by a strongly enhanced elongation rate of the petioles enabling them to reach the surface. Other factors, among them cell wall loosening enzymes have been shown to play a role as well.

Abscisic Acid↗
PubMed1996

An Ethylene-Mediated Increase in Sensitivity to Auxin Induces Adventitious Root Formation in Flooded Rumex palustris Sm.

The hormonal regulation of adventitious root formation induced by flooding of the root system was investigated in the wetland species Rumex palustris Sm. Adventitious root development at the base of the shoot is an important adaptation to flooded conditions and takes place soon after the onset of flooding. Decreases in either endogenous auxin or ethylene concentrations induced by application of inhibitors of either auxin transport or ethylene biosynthesis reduced the number of adventitious roots formed by flooded plants, suggesting an involvement of these hormones in the rooting process. The rooting response during flooding was preceded by increased endogenous ethylene concentrations in the root system. The endogenous auxin concentration did not change during flooding-induced rooting, but a continuous basipetal transport of auxin from the shoot to the rooting zone appeared to be essential in maintaining stable auxin concentrations. These results suggest that the higher ethylene concentration in soil-flooded plants increases the sensitivity of the root-forming tissues to endogenous indoleacetic acid, thus initiating the formation of adventitious roots.

Journal Article↗
PubMed1999

1-aminocyclopropane-1-carboxylate oxidase activity limits ethylene biosynthesis in Rumex palustris during submergence.

Submergence strongly stimulates petiole elongation in Rumex palustris, and ethylene accumulation initiates and maintains this response in submerged tissues. cDNAs from R. palustris corresponding to a 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene (RP-ACO1) were isolated from elongating petioles and used to study the expression of the corresponding gene. An increase in RP-ACO1 messenger was observed in the petioles and lamina of elongating leaves 2 h after the start of submergence. ACC oxidase enzyme activity was measured in homogenates of R. palustris shoots, and a relevant increase was observed within 12 h under water with a maximum after 24 h. We have shown previously that the ethylene production rate of submerged shoots does not increase significantly during the first 24 h of submergence (L.A.C.J. Voesenek, M. Banga, R. H. Thier, C.M. Mudde, F.M. Harren, G.W.M. Barendse, C.W.P.M. Blom [1993] Plant Physiol 103: 783-791), suggesting that under these conditions ACC oxidase activity is inhibited in vivo. We found evidence that this inhibition is caused by a reduction of oxygen levels. We hypothesize that an increased ACC oxidase enzyme concentration counterbalances the reduced enzyme activity caused by low oxygen concentration during submergence, thus sustaining ethylene production under these conditions. Therefore, ethylene biosynthesis seems to be limited at the level of ACC oxidase activity rather than by ACC synthase in R. palustris during submergence.

Aerobiosis↗
PubMed1972

Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts.

High germination of curly dock (Rumex crispus L.) seeds is evident after suitable imbibition and temperature shift treatment, but germination at constant temperatures fails without an input of far red-absorbing form of phytochrome. Preliminary imbibitions at high temperatures (30 C) sharply reduce germination induced by temperature shifts. High germination may be restored by low energies of red radiation, or by brief far red adequate for the photosteady state. Prolonged far red during imbibition also nullifies temperature shift-induced germination. After prolonged far red, high germination may be restored by red radiation of an energy dependent upon the duration of the far red treatment. The evidence supports the conclusion that dark germination induced by temperature shifts arises from the interaction of pre-existent far red-absorbing form of phytochrome in the mature seeds with the temperature shift.

Journal Article↗
PubMed1973

Phytochrome Transformation and Action in Seeds of Rumex crispus L. during Secondary Dormancy.

Promotion of germination by red light fails after prolonged dark imbibition of Rumex crispus L. seeds, indicative of a secondary dormancy. The degree and rate of inception of the dormancy increases with increasing temperature. Following establishment of the dormancy, germination response to red light can be restored by either prolonged cold treatment or brief high temperature shifts. Loss of phytochrome was not a factor in the initial establishment of the dormancy. When the seeds are in secondary dormancy, the chromophore of phytochrome can be transformed to the far red-absorbing form, but the far red-absorbing form cannot induce germination. The responses to changes in temperature suggested dependence of germination on order left arrow over right arrow disorder transitions in components of the seeds.

Journal Article↗
PubMed1974

Energy Metabolism of Rumex Leaf Tissue in the Presence of Senescence-regulating Hormones and Sucrose.

Hormones which inhibit senescence of Rumex leaf tissue in the dark include gibberellin A(3), and the cytokinins 6-benzylamino purine and zeatin. These hormones inhibit respiratory metabolism in this tissue, but do not change the pattern or total amount of oxygen consumption during senescence. Abscisic acid, a senescence accelerator, correspondingly stimulates oxygen consumption. This correlation of senescence rate and respiration rate holds with regard to the hormone concentrations effective and the continued activity of the hormones when added after the lag phase of chlorophyll breakdown. Transfer experiments show that the respiratory inhibition due to gibberellin A(3) and the promotion due to abscisic acid become established within 3 hours of hormone addition. When gibberellin A(3) and zeatin were rapidly added to narrow strips of tissue, no inhibitions of oxygen uptake were observed in the first 12 minutes. Senescence-inhibiting concentrations of sucrose strongly stimulate respiratory meabolism, raise the respiratory quotient, and cause inhibition of chlorophyll and protein breakdown which is distinct from the effect of gibberellins or cytokinins.It is proposed that the gibberellins and cytokinins may act by inhibiting a rate-limiting process in the metabolism of starving leaf tissue. This rate-limitation hypothesis envisions a possibly subtle action of the hormone which retards but does not alter the pattern of macromolecular changes during cell autolysis.

Journal Article↗
PubMed1976

Photosynthesis, Dark Respiration, and Growth of Rumex patientia L. Exposed to Ultraviolet Irradiance (288 to 315 Nanometers) Simulating a Reduced Atmospheric Ozone Column.

Net photosynthesis, dark respiration, and growth of Rumex patientia L. exposed to a ultraviolet irradiance (288-315 nanometers) simulating a 0.18 atm.cm stratospheric ozone column were determined. The ultraviolet irradiance corresponding to this 38% ozone decrease from normal was shown to be an effective inhibitor of photosynthesis and leaf growth. The repressive action on photosynthesis accumulated through time whereas leaf growth was retarded only during the initial few days of exposure. Small increases in dark respiration rates occurred but did not continue to increase with longer exposure periods. A reduction in total plant dry weight and leaf area of approximately 50% occurred after 22 days of treatment, whereas chlorophyll concentrations remained unaltered.

Journal Article↗
PubMed1982

Metabolism of l-Threonic Acid in Rumex x acutus L. and Pelargonium crispum (L.) L'Hér.

l-Threonic acid is a natural constituent in leaves of Pelargonium crispum (L.) L'Hér (lemon geranium) and Rumex x acutus L. (sorrel). In both species, l-[(14)C]threonate is formed after feeding l-[U-(14)C]ascorbic acid to detached leaves. R. acutus leaves labeled with l-[4-(3)H]- or l-[6-(3)H]ascorbic acid produce l-[(3)H]threonate, in the first case internally labeled and in the second case confined to the hydroxymethyl group. These results are consistent with the formation of l-threonate from carbons three through six of l-ascorbic acid. Detached leaves of P. crispum oxidize l-[U-(14)C] threonate to l-[(14)C]tartrate whereas leaves of R. acutus produce negligible tartrate and the bulk of the (14)C appears in (14)CO(2), [(14)C]sucrose, and other products of carbohydrate metabolism. R. acutus leaves that are labeled with l-[U-(14)C]threonate release (14)CO(2) at linear rate until a limiting value of 25% of the total [U-(14)C]threonate is metabolized. A small quantity of [(14)C]glycerate is also produced which suggests a process involving decarboxylation of l-[U-(14)C]threonate.

Journal Article↗
PubMed1984

Prevention of Action of Far-Red-Absorbing Phytochrome in Rumex crispus L. Seeds by Ethanol.

Phytochrome-enhanced germination of curled dock (Rumex crispus L.) seeds is further stimulated by pretreatments in solutions of 0.5 to 2 molar methanol and 0.03 to >/= 0.3 molar 2-propanol during a 2-day 20 degrees C imbibition. Similar pretreatments in 0.1 molar ethanol, acetaldehyde, and n-propanol inhibit phytochrome-enhanced germination. If exposure to ethanol is delayed until 16 hours after a red irradiation, seeds escape the ethanol inhibition indicating a mechanism other than toxicity. The rate of escape from ethanol inhibition roughly parallels the escape from phytochrome control in seeds held in water only, indicating possible ethanol effects on phytochrome. It was found that ethanol pretreatment prevents the far-red absorbing form of phytochrome (Pfr) from acting but does not accelerate dark decay or prevent transformation. Ethanol inhibition may be prevented if ethanol pretreatment is at 10 degrees C instead of 20 degrees C, or may be overcome by transferring ethanol-pretreated seeds to 10 degrees C in water. Similarly, ethanol inhibition can be overcome by a 2-hour 40 degrees C temperature shift concluding the pretreatment. It is proposed that the ethanol causes perturbations at a membrane which prevent Pfr from acting.

Journal Article↗
PubMed1985

Analysis of the Effect of Light and Temperature on the Fluence Response Curves for Germination of Rumex obtusifolius.

Both red light (10 minutes) and 35 degrees C treatment (60 minutes) stimulate the germination of seeds of Rumex obtusifolius otherwise maintained in darkness at 25 degrees C. Fluence response curves were determined for the effect of red light to stimulate germination of seeds with and without 35 degrees C treatment. The endogenous far-red absorbing form (Pfr) level in the seeds was determined using short saturating fluences of wavelengths of light which maintain different proportions of phytochrome as Pfr at equilibrium. In the seed batches investigated, the endogenous Pfr level was found to be 4% or less of the total phytochrome. High dark germination after 35 degrees C treatment does not result from an increase in sensitivity of the whole population to Pfr. Calculated fluence response curves for germination which best fit the experimental data suggest that seeds germinate in darkness after 35 degrees C treatment because of a nonphytochrome-related process (overriding factor).

Journal Article↗
PubMed1992

CO(2) Inhibits Respiration in Leaves of Rumex crispus L.

Curly dock (Rumex crispus L.) was grown from seed in a glasshouse at an ambient CO(2) partial pressure of about 35 pascals. Apparent respiration rate (CO(2) efflux in the dark) of expanded leaves was then measured at ambient CO(2) partial pressure of 5 to 95 pascals. Calculated intercellular CO(2) partial pressure was proportional to ambient CO(2) partial pressure in these short-term experiments. The CO(2) level strongly affected apparent respiration rate: a doubling of the partial pressure of CO(2) typically inhibited respiration by 25 to 30%, whereas a decrease in CO(2) elicited a corresponding increase in respiration. These responses were readily reversible. A flexible, sensitive regulatory interaction between CO(2) (a byproduct of respiration) and some component(s) of heterotrophic metabolism is indicated.

Journal Article↗
PubMed2000

Inhibitory effect of Rumex Japonicus Houtt on the porphyrin photooxidative reaction.

Rumex Japonicus Houtt (RJH), a plant indigenous to Okinawa, Japan, has been used traditionally by the local people for treatment of acute and chronic cutaneous diseases; however, its pharmacological effect is not clearly understood. To investigate its active function, we examined the antioxidative effect of RJH on the hematoporphyrin-induced photooxidative reaction. We measured intracellular reactive oxygen species (ROS) in cultured transformed human vascular endothelial cells (ECV-304) by flow cytometry, lipid peroxide (LPO) in erythrocyte ghosts by spectrofluorometry, and hemolysis by spectrophotometry. Results showed the generation of intracellular ROS in ECV-304, LPO production in erythrocyte ghosts, and hemolysis after visible light irradiation in the presence of hematoporphyrin. In the RJH root extract treated group, generation of intracellular ROS, LPO production, and hemolysis were inhibited significantly. It has been reported that the RJH root contains emodin and chrysophanic acid. In our study, three fractions were separated from the RJH root extract by thin layer chromatography (TLC). We found that fraction 1 (near the origin) showed a strong inhibitory effect on LPO levels; however, fraction 2 (equal to emodin) and fraction 3 (equal to chrysophanic acid) showed no inhibitory effect on LPO levels. Our experiments verified that RJH has an antioxidative effect against photohemolysis and supports our hypothesis that RJH may have potential as a protective agent against oxidative stress associated with some diseases such as porphyrias.

Absorption↗
PubMed1980

City spore concentrations in the European Economic Community (EEC). IV. Summer weed pollen (Rumex, Plantago, Chenopodiaceae, Artemisia), 1976 and 1977.

This paper describes observations on the airborne pollen concentrations of four anemophilous weeds of very common occurrence in Western Europe, viz. Rumex spp .(sorrel and dock), Plantago spp. (plantain), Chenopodiaceae (goosefoot family) and Artemisia spp. (mugwort). Comparative results are recorded from London, Leiden, Brussels, Munich and Marseilles for the summers of 1976 and 1977 and this study is one of a series involving international collaboration between workers in cities of the European Economic Community. The literature on the clinical significance of summer weed pollen is reviewed and it is concluded that the pollen of Artemisia is likely to be of importance in areas where the weed is of common occurrence in late summer. The pollen of the other summer weeds is unlikely to be important, but may contribute to the problems of the pollen sensitive patient under exceptional circumstances.

Air↗
PubMed2000

Molecular cytogenetic analysis of supernumerary heterochromatic segments in Rumex acetosa.

The dioecious plant Rumex acetosa shows intraspecific karyotype variation, caused by supernumerary heterochromatic segments or DAPI (4',6-diamidino-2 phenylindole)-bands at the ends of the short arms of three pairs of autosomes. A DNA sequence (RAE730) specific to the supernumerary heterochromatic segments was cloned and sequenced. RAE730 was about 730 bp and AT-rich (71% AT-content). Using fluorescence in situ hybridization (FISH), RAE730 was localized in the supernumerary DAPI-positive heterochromatic segments on several mitotic chromosomes and chromocenters in interphase nuclei, but not in the DAPI-bands of Y or B chromosomes. RAE730 was tandemly arranged in the genome, and the copy number varied between plants from 40000 to 304000 copies per 2C, corresponding to the relative amount of supernumerary heterochromatic segments per genome. These results indicate that the karyotype variation caused by the supernumerary heterochromatic segment was generated by amplification or reduction of the tandem repeats of RAE730.

Base Sequence↗
PubMed2001

Effect of the aqueous extract of Rumex patientia on xylol and hyaluronidase induced capillary permeability compared to indomethacin.

In this study, the effect of an aqueous extract of Rumex patientia L. (Polygonaceae) (D-1) on capillary permeability which was induced by xylol and hyaluronidase was investigated. Experiments were conducted on rabbits according to Monakova and Matusis methods. The effects of D-1 were compared to those of indomethacin, which was used as a control throughout the experiment. Both D-1 (100 mg/kg) and indomethacin (10 mg/kg) were administered orally. As a result, D-1 inhibited capillary permeability, which was induced by xylol and hyaluronidase, and it was found that it was as effective as indomethacin.

Animals↗
PubMed2001

Analgesic and antipyretic activities of Rumex patientia extract on mice and rabbits.

The aqueous extract from the roots of Rumex patientia L. (Polygonaceae) was investigated for its analgesic and antipyretic effects on mice and rabbits. When the activities of the extract were evaluated in comparison with acetylsalicylic acid (ASA), indomethacin and morphin, it was found to possess significant analgesic and antipyretic activities.

Analgesics, Non-Narcotic↗