Showing papers in "Biologia Plantarum in 1984"
TL;DR: A lectin was isolated from Canavalia brasiliensis Mart.
Abstract: A lectin was isolated fromCanavalia brasiliensis Mart seeds by combining solubility fractionation with affinity chromatography on Sephadex G-50 The lectin showed a carbohydrate specificity for D-mannose (D-glucose) binding and a requirement for Ca2+ and Mn2+ All the hemagglutinating activity was found in the cotyledons and the presence of the lectin was followed during the first 15 days of plant germination, through the activity against rabbit erythrocytes, the presence of the “lectin peak” in Sephadex G-50 affinity chromatography, presence of the “lectin bands” in SDS-polyacrylamide gel electrophoresis and the “lectin arcs and rockets” in immunoelectrophoresis in agarose gel On application of all these methods the lectin showed a differentiated metabolism, disappearing more slowly than the other high molecular weight proteins of the seed
88 citations
TL;DR: Rapid multiplication of axillary shoots of oak and linden has been achieved on broad-leaved tree medium (BTM) and woody plant medium (WPM) containing low level of cytokinin (BAP 0.2–1.0 mg l-1) and on low salt, low sucrose media, containing lowlevel of auxins.
Abstract: Rapid multiplication of axillary shoots of oak and linden has been achieved on broad-leaved tree medium (BTM) and woody plant medium (WPM) containing low level of cytokinin (BAP 0.2–1.0 mg l-1). High rooting percentages (80–95%) were obtained on low salt, low sucrose media, containing low level of auxins. Rooted plants were transplanted into pots containing a mixture of peat and perlite. Most of the plants (90–95%) survived the transfer. After the hardening off period the new plants were planted in the field.
76 citations
TL;DR: In both C3 and C4 species RD and Rm increased with temperature in the temperature range studied, and significant correlation between RD and RM and between RG and PG was found.
Abstract: The rates of maintenance and growth components of leaf dark respiration of a C3 plant (Phaseolus vulgaris L.) and C4 plant (Zea mays L.) as affected by temperature were studied using the McCree concept. Respiration rates were measured by means of infrared gas analysis in a closed gas exchange system. In both C3 and C4 species RD and Rm increased with temperature in the temperature range (15–62 °C) studied. RG depended on temperature with an optimum near the temperature optimum of gross photosynthetic rate, Pg. Significant correlation between RD and RM and between RG and PG was found.
31 citations
TL;DR: The preparation had 3′-nueleotidase activity even after further purification by DEAE-cellulose chromatography, and the extracellular nuclease of tobacco pollen can be classified as plant nucleasing I (EC 3.1.30.x).
Abstract: Proteins diffusing from tobacco pollen grains exhibit different phosphohydrolytic activities. Molecular sieving produces nuclease fractionation into forms I, II and III with apparent molecular masses ≥ 60 × 103, 32.9 × 103 and 24.6 × 103, respectively, and separation of principal forms II and III from phosphatase and major part of 5′- and 3′-nucleotidase activities. These forms did not differ in the mode of substrate attack and were combined for further enzyme characterization.
25 citations
TL;DR: The dens i ty of s t o m a t a in leaves of different eeo types of P h r a g m i t e s c o m m u n i s are revealed.
18 citations
TL;DR: Water-stress for 10d at different developmental stages, affected relative water content and leaf water potential of plants, but the removal of stress could not improve these parameters to the same extent as at the vegetative stage.
Abstract: Water-stress for 10d at different developmental stages, affected relative water content and leaf water potential of plants. Subsequent rewatering removed these effects. Water stress lowered the contents of chlorophyll, protein, RNA and the activity of catalase, while it increased free proline accumulation and activities of protease, RNase and peroxidase. An overall improvement in biochemical parameters was achieved as soon as the stress was withdrawn by watering and this was reflected in subsequent developmental stages. Water-stress at the reproductive stages induced similar changes as in the vegetative stage but the removal of stress could not improve these parameters to the same extent as at the vegetative stage. In consequence, stress applied at the vegetative stage augmented yield parameters but when applied at the reproductive stage it significantly reduced the yield.
18 citations
TL;DR: The results indicate that the inhibitory effect of high nitrate concentration on whole nodule metabolism is nonspecific in nature.
Abstract: Nitrate (20 mM) applied to the root medium of 28-day-old nodulated pea plants (Pisum sativum L., cv. Jupiter) immediately retarded nodule growth and inhibited root nodulation. Acetylene-reducing and H2-evolving nitrogenase activities were also significantly inhibited. The inhibitory effect of nitrate on nodule respiration was less pronounced while the respiration of roots was increased after the addition of nitrate. The levels of cytosol glutamine synthetase and nitrate reductase in nodule cytosol were permanently decreased from the 4th day after nitrate application. These results indicate that the inhibitory effect of high nitrate concentration on whole nodule metabolism is nonspecific in nature.
14 citations
TL;DR: Under the given conditions, the cytokinins proved to be much more powerful inhibitors than DHPA, whereas adenine and adenosine were less impairing.
Abstract: 3-day-old seedlings ofVicia faba L. were put onto a diluted Knop’s solution containing the tested substances within the intentional concentration range and left there for 7 days. In comparison with controls in plain nutrient solution, the DHPA treated plants revealed a suppression of shoot and root development. The main root growth was less sensitive than root branching. 8 h exposure was sufficient to gain a distinct effect. Microscopically the block of mitosis and/or cytokinesis, the formation of binucleate cells and local tissue damage were revealed. Under the given conditions, the cytokinins (BAP, (9R)BAP, iP, (9R)iP) proved to be much more powerful inhibitors than DHPA, whereas adenine and adenosine were less impairing.
14 citations
TL;DR: Contents of individual carotenoids in the fruits of Ramillete cultivar of Capsicum annuum L. changed during ripening of recently harvested fruits or fruits stored 15 d in a dark and cool room.
Abstract: Contents of individual carotenoids in the fruits of Ramillete cultivar ofCapsicum annuum L. changed during ripening of recently harvested fruits or fruits stored 15 d in a dark and cool room. β-carotene and β-cryptoxanthin contents rose to a maximum and then declined, while the contents of other earotenoids rose to a rather steady level. Capsanthin was the main carotenoid which together with capsorubin were responsihle for the ripening colour.
13 citations
TL;DR: The effects of PEG 6000 priming on germination performance of aged wheat seed lots have been studied and a correct application of osmopriming treatment indicated a relationship between the pattern of water absorption, the reactivation of mitotic activity and the start and synchronization of germination.
Abstract: The effects of PEG 6000 priming on germination performance of aged wheat seed lots have been studied. A correct application of osmopriming treatment indicated a relationship between the pattern of water absorption, the reactivation of mitotic activity and the start and synchronization of germination. The possibility of controlling pregerminative events by means of this treatment is discussed on the physiological basis of seed germination.
12 citations
TL;DR: In this paper, a stock iron solution prepared by chelation of ferrous sulphate with an equimolar quantity of the complexone Na2EDTA was used to detect up to 10% free FeII ions.
Abstract: In standardMurashige-Skoog medium, particularly at pH higher than 5.0 and after heat sterilization, there is a tendency for turbidity or a sediment to appear, and for the acidity to increase by 0.2 to 0.5 degrees pH. The sediment is an amorphous precipitate of ferric phosphate and partly also of ferrous phosphate. In a stock iron solution prepared by chelation of ferrous sulphate with an equimolar quantity of the complexone Na2EDTA. up to 10% free FeII ions could be detected. By titration of a concentrated complexon solution it was found that in the presence of an excess of Na2EDTA (at the approximate molar ratio FeII: Na2EDTA 1: 2) chelation of this free iron takes place to such an extent that its concentration falls to as little as 0.1%. Media with iron stabilized in this way are quite clear and maintain the adjusted pH for up to several weeks. The heat sterilization, too, does not lead to any precipitation or to a shift in pH within the broad range of adjusted values pH 4.8 – 6.0. We also attempted to increase the relatively low buffering capacity of Murashige-Skoog medium. The addition of sodium citrate (1.25 mmol 1-1) and particularly of citrate-phosphate buffer (at a final concentration of 1.97 mmol citric acid and 6.07 mmol dibasic sodium phosphate per litre of medium) to the Murashige-Skoog medium considerably increased its buffering capacity, so that at the end of the subculture interval of tobacco cell suspensions the adjusted acidity changed only slightly (pH 5.40 ± 0.15). A thorough evaluation of the growth parameters of tobacco batch cultures (cell counts, vital staining, kinetics of DNA and protein synthesis) failed to reveal any negative effect either of additional chelation or of the buffering components.
TL;DR: It may be proposed that plant tissue culture media have no direct effect on induction of mitotic aberrations in plant tissue cultures in vitro.
Abstract: The effect of plant tissue culture medium with different concentrations and combinations of growth regulators (kinetin, indol-3-ylacetic acid, 2,4-dichlorophenoxyacetic acid) was evaluated on mitosis ofAllium sativum meristem root tip cells. Different combinations of growth regulators at low concentrations had no effect on induction of mitotic aberrations or inhibition of mitotic activity. Inhibition of mitotic activity, a tendency to chromosome stickiness and clumping and a slight increase in the frequency of mitotic aberrations were observed at higher concentrations. It may be proposed that plant tissue culture media have no direct effect on induction of mitotic aberrations in plant tissue culturesin vitro.
TL;DR: In this paper, the long-term effects of glycine betaine on water use efficiency, dry matter production and net photosynthetic rate have been studied, and the results showed that applied glycinebetaine enhanced the WUE and the grain yield of wheat.
Abstract: Long-term effects of glycinebetaine on water use efficiency (WUE), dry matter production and net photosynthetic rate have been studied. Applied glycinebetaine enhanced the WUE and the grain yield of wheat.
TL;DR: The aim of this work was to monitor the changes in the cell membrane permeability due to a change in the water potential of the cells, especially during plasmolysis and deplasmolytic.
Abstract: The overall washing out of ions, especially86Rb+ (as the tracer for K+), from hypocotyl segments of pumpkin (Cucurbita pepo L.) into distilled water or a CaCl2 solution was studied, during plasmolysis with a saccharose solution and during deplasmolysis. Compartimental analysis was used to evaluate the86Rb+ washing out kinetics. During plasmolysis, the washing out of86Rb+ increases, due to two processes whose half-times are lower than those during washing out into the CaCl2 solution. During deplasmolysis, the permeability of plasmalemma and tonoplast is substantially descreased, leading to washing out of most86Rb+ from the cells. Plasmolysis differs from a mere decrease in the turgor pressure in the fact that after exchange for a hypotonic solution the membranes are irreversibly damaged. The aim of this work was to monitor the changes in the cell membrane permeability due to a change in the water potential of the cells, especially during plasmolysis and deplasmolysis.
TL;DR: The mature nodules of esculenta Moench contained higher levels of indolyl acetic acid (IAA), cytokinins (CK), gibberellic acid (GA)-like substances and more active in nitrogenase (N2-ase) activity than young or old ones.
Abstract: The mature nodules ofLens esculenta Moench. contained higher levels of indolyl acetic acid (IAA), cytokinins (CK), gibberellic acid (GA)-like substances and more active in nitrogenase (N2-ase) activity than young or old ones. Synthesis of IAA and its metabolism was found to be controlled by tryptophan (tryp) and phenol metabolism, respectively, in nodules of different ages. An abscisic acid (ABA)-like substance being a ‘late growth phase’ hormone, was highest in old nodules.
TL;DR: Simultaneously with optimal morphoregulatory effect in androgenesis and somatic embryogenesis, vitality of tissue culture will be lengthened and ageing as well as necrosis of the cultures be decreased.
Abstract: The addition of Na2EDTA to a minimal medium (agar, sucrose) deprived of cations produces no morphoregulatory effect. This effect is induced only by the addition of iron. Traces of iron present in the agar are sufficient for the development of globular embryoid into a complete plant. The traces of iron in distilled water and sucrose (p. a.) are insufficient for the morphoregulation. The marked difference between the necessary limiting amount of chelate and necessary limiting amount of iron in non-modified media is explained by the presence of other cations, which saturate and thereby inactivate a greater part of Na2EDTA. It is recommended to decrease the amount of iron and leave the commonly used amount of chelate in the prepared media. Simultaneously with optimal morphoregulatory effect in androgenesis and somatic embryogenesis, vitality of tissue culture will be lengthened and ageing as well as necrosis of the cultures be decreased.
TL;DR: In this article, the transpiration rate of the first leaf in 8-day plants of spring barley was measured in dependence on the water saturation deficit (ΔW sat) in an open gas exchange system with a thermocouple psychrometer.
Abstract: In an open gas exchange system with a thermocouple psychrometer the transpiration rate of the first leaf in 8-day plants of spring barley was measured in dependence on the water saturation deficit (ΔW
sat). The plants were cultivated in Richter’s nutrient solution, either complete, or deficient in nitrogen or phosphorus. The cuticular transpiration (as measured in the dark) was unaffected by N and P deficiency. The N deficiency reduced the transpiration rate by increasing stomatal resistance since full water saturation of the leaf (67% rate of the control variant) up to stomatal closing at Δ Wsat = 14%. The P deficiency does not affect the transpiration rate at initial phases of wilting, but the stomata close only at a higher Δ Wsat (25%) than those in the control.
TL;DR: Red cabbage (tolerant) shows higher Root Cationic Exchange Capacity than tomato (sensitive) or radish (intermediate) and at low NaCl concentrations, tomato accumulates the greatest quantities of sodium; but Na+ translocation remains proportional to the quantity absorbed in the three plants.
Abstract: Adsorption, absorption and translocation of sodium were compared in three species showing an ascending degree in tolerance to salinity: red cabbage (tolerant) shows higher Root Cationic Exchange Capacity than tomato (sensitive) or radish (intermediate). At low NaCl concentrations, tomato accumulates the greatest quantities of sodium; but Na+ translocation remains proportional to the quantity absorbed in the three plants. At high salt concentrations, diffusive phenomena explain similar accumulation in every plant, but red cabbage quickly localises 50% of Na+ amount in cotyledons, while this element stays stored in tomato roots. The consequence of these three nutrition phases was discussed in relation to the behaviour observed at the germination time of these same plants.
TL;DR: The growth of transformed calli was stimulated by vitamins and partly inhibited by growth regulators in concentrations used for the maintenance of untransformed calli, and hormonal autonomy was observed in the light where crown gall calli readily differentiated into teratomas and (sometimes fertile) plants.
Abstract: Crown galls induced onArabidopsis thaliana plants by octopine or nopaline strains ofAgrobacterium tumefaciens were grownin vitro on different media. Dark growth of all tumor tissues was strictly hormone-dependent. In contrast, hormonal autonomy was observed in the light where crown gall calli readily differentiated into teratomas and (sometimes fertile) plants. Differentiating tissues always grew more vigorously than subtended calli. The growth of transformed calli was stimulated by vitamins and partly inhibited by growth regulators in concentrations used for the maintenance of untransformed calli. Crown gall calli, teratomas and sometimes regenerated plants were shown to express lysopine or nopaline dehydrogenase activities.
TL;DR: Succinate dehydrogenase activity was the most affected enzyme among the respiratory chain enzymes and was significantly inhibited by all the above phenolic compounds at 1-4M or 5 10-5M concentrations with the exception of gallic acid.
Abstract: The effect of derivatives of benzoic and cinnamic acids, quereetin,p-benzoquinone, and 2,5-dimethylbenzoquinone on oxygen consumption mitoehondrial suspensions and on the activity of some respiratory chain enzymes was studied. Benzoquinone and 2,5-dimethylbenzoquinone highly significantly inhibited the respiration and phosphorylation rates and malate- and succinate dehydrogenase activities. Chlorogenic acid, similarly as the quinones, very significantly inhibited the activities of the studied dehydrogenases but did not affect cytochrome oxidase. Oxygen consumption by intact mitochondria was not inhibited, only the oxidativo phosphorylation was significantly uncoupled. Quereetin significantly enhanced dehydrogenase activities and completely inhibited cytochrome oxidase activity. The respiration and phosphorylation activities of the mitochondria were significantly inhibited by quereetin. The effect of the other phenolic compounds studied on respiration and phosphorylation activities was not significant. Succinate dehydrogenase activity was the most affected enzyme among the respiratory chain enzymes. It was significantly inhibited by all the above phenolic compounds at 1-4M or 5 10-5M concentrations with the exception of gallic acid.
TL;DR: The results suggest that salicylate elicits some alterations interfering with the control of, stomatal movements, possibly affecting the integrity of cell membranes.
Abstract: Salicylate administered to detached tobacco (Nicotiana tabacum L.) leaves kept in the light rapidly induced an increase in stomatal resistance. This effect was not the result of water stress. Both the concentration of salicylate and the duration of the application to leaves affected the extent of the stomatal response. Application of salicylate for short periods showed that, once the stomatal response started, it was maintained for long period of time in the absence of further supply. K+ or Ca2+ were able to lower the stomatal resistance induced by salicylate, but only when both the ions were administered together with salicylate the stomatal closure was prevented. The results suggest that salicylate elicits some alterations interfering with the control of, stomatal movements, possibly affecting the integrity of cell membranes.
TL;DR: In this paper, it was shown that the calculation of the intercellular CO2 concentration on the basis of the premise that the resistance of stomata equals that of the leaf, is affected by a considerably high error.
Abstract: Under increasing water saturation deficit of leaves of young bailey plants, the proportion of the cuticular transpiration may be higher than 10%, as usually anticipated. In this case the calculation of the intercellular CO2 concentration on the basis of the premise, usually employed, that the resistance of stomata equals that of the leaf, is affected by a considerably high error.
TL;DR: A growth-correlative effect of the root becoming evident in dependence on plant ontogenesis in changes of IAA content and activities of the above enzymes catalysing IAA synthesis is indicated.
Abstract: In five-day-old etiolated pea seedlings an increase in IAA content and in L-tryptophan aminotransferase (TAT) and L-tryptophan dehydrogenase (TDH) activities in the apical part of the epicotyl was found 12 h after root excision, which was followed by a decrease up to 48 h. In ten-day-old seedlings a continuous decrease in IAA, TAT and TDH levels in the apical part of the epicotyl was recorded up to 48 h after root excision. This indicates a growth-correlative effect of the root becoming evident in dependence on plant ontogenesis in changes of IAA content and activities of the above enzymes catalysing IAA synthesis.
TL;DR: PAA was able to promote the flow of14C-ABA in the acropetal direction and PAA-initiated thickening growth was probably the cause of this promotion.
Abstract: The mode of transport and regulative properties of phenylacetic acid (PAA) were studied in 11-cm long segments of pea epicotyls capable of growth. The transport of PAA m both the basipetal and aeropetal direction was limited to tissues situated immediately below and/or above the site of its application. PAA was able to promote the flow of14C-ABA in the acropetal direction. PAA-initiated thickening growth was probably the cause of this promotion.
TL;DR: In this paper, a study on the effect of increasing photon fluence rate (I) at a unilateral irradiation of adaxial and abaxial blade surface of maize leaves of various insertion levels on net photosynthetic CO2 uptake (P n ) by the leaves, as well as the contribution of individual surfaces to P n, and the significance of or relationship between the stomatal (g s ) and intracellular (gm) conductances at the CO2 transport.
Abstract: A study was made on the effect of increasing photon fluence rate (I) at a unilateral irradiation of adaxial (normal leaf position) and abaxial (inverse leaf position) blade surface of maize leaves of various insertion levels on net photosynthetic CO2 uptake (P n ) by the leaves, as well as the contribution of individual surfaces toP n of the leaves, and the significance of, or relationship between the stomatal (g s ) and intracellular (gm) conductances at the CO2 transport.P n of leaves of various age according to their insertion level was unaffected by the direction of incident irradiation. Upon irradiation of the leaves in normal and inverse position the contribution of the adaxial and abaxial surfaces toP n ,g s and gm was different. On irradiating the leaves in normal position, the contribution of the irradiated adaxial surface to the characteristics mentioned made on the average 55% of total values, the contribution of the abaxial surface irradiated in inverse position made on the average 70% inP n andg m , and 80% ing s . At lowerI’s g m was higher thang s both in irradiated and non-irradiated surfaces. The ratio ofg s to gm gradually got square with increasingI. In the irradiated adaxial surface the equilibrium (g s /g m = 1.0) took place at the highestI’s, in the irradiated abaxial surface between 500 to 1000 μmol m−2 s−1. The significance of the ratiog m in the CO2 transport through the individual surfaces is discussed.
TL;DR: The sensitivity of stomata to water stress increased during ontogeny of primary bean leaves growing under constant environmental conditions and the decrease in both adaxial and abaxial epidermal conductances was induced by slightly more negative values of leaf water potential in young than in mature and especially old leaves.
Abstract: The sensitivity of stomata to water stress increased during ontogeny of primary bean leaves growing under constant environmental conditions: the decrease in both adaxial and abaxial epidermal conductances was induced by slightly more negative values of leaf water potential in young than in mature and especially old leaves. However, these differences were less expressive than the differences mentioned in the literature for leaves of different insertion level, where adaptations to microclimatic conditions in different canopy layers in addition to ontogeny may occur.
TL;DR: Calli under study showed autonomy for cytokmms independently whether cultivated on the light or m the dark when cultivated in intense light, they were able to grow, either transiently or permanently, on the medium without any growth regulators.
Abstract: The growth ofArabidopsis thaliana calli on media without growth regulators was studied Calli under study showed autonomy for cytokmms independently whether cultivated on the light or m the dark When cultivated in intense light, they were able to grow, either transiently or permanently, on the medium without any growth regulators In the dark, they were strictly dependent on 2,4 D m the medium Both the intensity of growth and the duration of the transient growth on the medium without growth regulators m the light decreased with the duration of the previous cultivation on the medium with growth regulators The intensity of growth on the medium without grow th regulators was best and the growth was permanent m the callus clone of spontaneous origin which was never treated by growth regulators The degree of chromosomal variability (assessed as the number of chromocentres) m this callus line was lower than that in calli induced on media with growth regulators and then transferred onto medium without growth regulatois.
TL;DR: The photoacoustic spectroscopic studies of purple pigmented leaves revealed the occurrence of anthocyanins and betalains in some local weed species growing on soils with low moisture levels.
Abstract: The photoacoustic spectroscopic studies of purple pigmented leaves revealed the occurrence of anthocyanins and betalains in some local weed species growing on soils with low moisture levels. The pigmentation intensities were higher in C4 plants than in C3 plants. An inverse correlation was observed between pigmentation intensities and soil moisture levels.
TL;DR: The interaction of senescence and phosphorus deficiency in determining phosphatase activities of Lemna minor has been examined in axenic cultures and the results are discussed in relation to possible functional significance of the enzyme activities.
Abstract: The interaction of senescence and phosphorus deficiency in determining phosphatase activities ofLemna minor has been examined in axenic cultures. Acid phosphatase activity increased in phosphorus deficiency, alkaline pyrophosphatase activity decreased during senescence and this decrease was exaggerated by phosphorus deficiency. The results are discussed in relation to possible functional significance of the enzyme activities.