Roots Of Pea Plants Research Articles

Metal tolerance and Cd phytoremoval ability in Pisum sativum grown in spiked nutrient solution.

In the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (Pisum sativum L.) were investigated. The tendency to accumulate cadmium in the relevant morphological parts of the plant (roots and shoots respectively)-bioaccumulation, the transfer of this element in the plant (translocation) and the physiological parameters of the plant through indicators of oxidative stress were determined. Model studies were carried out at pH values 6.0 and 5.0 plant growth conditions in the hydroponic cultivation. It was shown that Cd accumulates mostly in plant roots at both pH levels. However, the Cd content is higher in the plants grown at lower pH. The Cd translocation factor was below 1.0, which indicates that the pea is an excluder plant. The contamination of the plant growth environment with Cd causes the increased antioxidant stress by the growing parameters of the total phenolic content (TPC), polyphenol oxidase activity (PPO), the malondialdehyde (MDA) and lipid peroxidation (LP). The results obtained showed that the supplementation with Si reduces these parameters, thus lowering the oxidative stress of the plant. Moreover, supplementation with Si leads to a lower content of Cd in the roots and reduces bioaccumulation of Cd in shoots and roots of pea plants.

The response of pea plants to ultraviolet B radiation and cytokinin

Aim. The effect of chronic ultraviolet B (UV-B) radiation and cytokinin benzylaminopurine (6-BAP) on the growth, content of photosynthetic pigments and hydrogen peroxide (HP) in leaves of pea plants (Pisum sativum L.) was studied. Methods. Pea plants cultivar Gotivsky were irradiated by chronic UV-B at a dose of 3.5 kJ/m2 per day during 5 days. Groups of the irradiated and non-irradiated plants were treated with 6-BAP after the end of the UV-B radiation. Length of shoots and roots of pea plants were measured during all time of experiment. Content of photosynthetic pigments and HP in leaves were determined during the experiment. Results. It was shown that plant growth delayed, content of photosynthetic pigments reduced, content of HP increased in the leaves after the chronic UV-B radiation of pea plants. The content of pigments increased and content of HP stabilized in pea leaves after the treatment of plants with 6-BAP. Conclusions. It was shown that chronic UV-B radiation of pea plants by dose of 3.5 kJ/m2 per day caused inhibition of plants growth, increasing HP content, decreasing photosynthetic pigments content in mature leaves. The BAP treatment of irradiated plants stimulated the restoration of photosynthetic pigments content in leaves.

Draft Genome Sequence of the Bacterium Cupriavidus sp. Strain D39, Inhabiting the Rhizosphere of Pea Plants (Pisum sativum L.).

We report the draft genome sequence of Cupriavidus sp. strain D39, associated with the roots of pea plants. The genome is characterized by a GC content of 63.62% and a total length of 7.7 Mbp and contains several putative genes associated with resistance to metals and plant growth promotion.

NAPHTALENE IS ESSENTIAL METABOLITE FOR SYNTHESIS OF N-PHENYL-2-NAPHTHYLAMINE AND PHTHALATES IN PISUM SATIVUM L.

N-phenyl-2-naphthylamine and phthalates are well known compounds, synthesized in chemical industry. These chemicals are known to be toxic for living organisms. At the same time N-phenyl-2-naphthylamine was found in plants, phthalates were found both in plants and bacteria. Currently, there are no data in scientific literature about the synthesis of N-phenyl-2-naphthylamine and phthalates in plant cells. Previously, we have established the presence of these compounds in root tissues and root exudates in legumes. The aim of this study was to find the ability of Pisum sativum L. to utilize naphthalene as a precursor for the synthesis of N-phenyl-2-naphthylamine and phthalates. As an object of study, roots of the etiolated pea seedlings, grown with 10-4 M naphthalene for 24 h, were used. Roots of seedlings grown on water were used as a control. Extracts, containing aromatic compounds were obtained by successive extraction with 80% ethanol and ethyl acetate from root seedlings, fixated with 95% ethanol. Using HPLC the concentrations of N-phenyl-2-naphthylamine, diethyl-, dibutyl- and bis(2-ethylhexyl)phthalates were estimated. To confirm the presence of phthalates in extracts, standard samples of corresponding compounds were used. Significant increases of N-phenyl-2-naphthylamine and phthalates concentrations in roots of pea plants, grown with naphthalene solution (compared to control plants), have shown that plant cells seem to use this compound as a necessary metabolite in biosynthesis of compounds mentioned above.

Studying the response of seedlings peas to soaking seeds tropylated aniline

The article presents the results of laboratory model experiment to study the responsiveness of peas to synthesized organic compound (tropylated aniline). When seeds are treated with substance in concentrations from 1×10-5% to 1×10-3% an increase in the mass 1 plant of pea. With an increase in the concentration of the substance up to 1×10-2% in the solution, the negative effect of the studied preparation on the plant increase. An inverse correlation has been established between aniline concentrations and biometric parameters of pea seedlings. Aniline had a mathematically proven positive effect on the concentration of soluble protein in sprouts and peroxidase activity in the roots of pea plants

Biotechnology of biological bacterial preparations used in resource-saving farming

The article presents materials on the use of selenium compounds in the production of biological fertilizers, the main active component of which being artificially cultivated nodule bacteria. The objects of research in this work were various types of bacterial organisms used to prepare bacterial fertilizers: symbiotic nitrogen-fixing bacteria (rhizoagrin, rhizotorfin for galega and pea) and free-living agrobacteria (agrophil). Sodium selenate (Na2SeO4) was used as a source of selenium. The most optimal concentration of selenium ions in the liquid culture of microorganisms was 10–4 g/kg. A positive effect of selenium on the titer of finished preparations was observed: on average for the study period Rhizobiumpisum (rhizotorfin for peas) and Agrobacter 10 (agrophil) on the variant with selenium exceeded that on the control variant by 35.2 and 26.6%, respectively. The absolute titer values of the finished preparations Rhizobiumpisum (pea rhizotorfin) and Agrobacter 10 (agrophil) on non-sterile peat turned out to be higher than on sterile peat, although the trend remained. The inoculation of pea seeds with bacterial preparations increased the number of nodules in the flowering phase on the roots of pea plants by 1.8–2.1 times compared with the control. The treatment of pea seeds with rhizotorfin activated by selenium compounds during its manufacture increased the grain yield by 0.51 t/ha (17.1%) compared with the control, and by 0.30 t/ha (10.0%) when inoculated with rhizotorfin.

INCREASING SOIL FERTILITY AS A RESULT OF THE ACCUMULATION OF NITROGEN BY LEGUMINOUS CROPS

Analysis of literary sources shows that legume-rhizobial systems annually fix nitrogen from the atmosphere in the amount of from 40 to 300 kg of per 1 ha of crop. Crops of legumes by Nitrogen fixation capabilities play an important role in saving and improvement of the natural soil fertility. It is known that in the process of the crop rotation with legumes the species composition of soil microorganisms is restored, as a result stable soil fertility rate is supported. Legumes plants are valuable siderata. Green legume fertilizer has a positive effect on increasing the productivity of plants, causes to the conservancy and increase of soil fertility. The plowing of the siderates leads to an increase in the humus content in the soil and the availability of phosphate treatment, a reduction in nitrogen gas losses from the soil. After decomposition and mineralization of leguminous siderata, the soil is replenished with nutritious macro- and microelements. Siderata is able to loosen heavy soils, improve their structure, and inhibit the growth of weeds that create water deficiency and reduce the content of minerals in the soil. Growing of peas leads to increased of the absorption efficiency of organic fertilizers by the following crops. The article approves the results of increasing the nitrogen-fixing ability of sowing pea with applying of the microbial preparation Bioinoculant and plant growth regulator Mars EL, and their role in increasing of biological nitrogen content for repair of soil fertility. It was established that the symbiotic activity of pea plants depends on the growth phase of the crop. The highest indexes of active nitrogen-fixing nodules on the roots of pea plants were found in the budding phase after pre-sowing seed complex treatment with Bioinoculant and growth regulator Mars EL. It was researched that he combined use of Bioinoculant and plant growth regulator Mars EL provided the increase of the mass of active nodules at the roots of the plant by 33% (phase of formation of 5-6 leaves), 38,8% (budding phase) and 22,8% (flowering phase) compared to the control. It was found that the use of inoculant and plant growth regulator with N30P30K30 fertilizer background leads to the greatest concentration of nodules on the main roots of the plants. The nodules had a pink color. In the technological process, the pre-sowing treatment of pea seeds with Bioinoculant and plant growth regulator Mars EL is an important perspective for improving the symbiotic activity of culture. This induces the reproduction of the soil's natural fertility. It is advisable to investigate the effect of inoculation and growth regulators with the different mechanism of action on the symbiotic activity of winter peas. Key words: soil fertility, legumes, siderata, symbiotic nitrogen fixation, inoculant, plant growth regulator

Role of Pea LTPs and Abscisic Acid in Salt-Stressed Roots.

Lipid transfer proteins (LTPs) are a class of small, cationic proteins that bind and transfer lipids and play an important role in plant defense. However, their precise biological role in plants under adverse conditions including salinity and possible regulation by stress hormone abscisic acid (ABA) remains unknown. In this work, we studied the localization of LTPs and ABA in the roots of pea plants using specific antibodies. Presence of LTPs was detected on the periphery of the cells mainly located in the phloem. Mild salt stress (50 mM NaCI) led to slowing plant growth and higher immunostaining for LTPs in the phloem. The deposition of suberin in Casparian bands located in the endoderma revealed with Sudan III was shown to be more intensive under salt stress and coincided with the increased LTP staining. All obtained data suggest possible functions of LTPs in pea roots. We assume that these proteins can participate in stress-induced pea root suberization or in transport of phloem lipid molecules. Salt stress increased ABA immunostaining in pea root cells but its localization was different from that of the LTPs. Thus, we failed to confirm the hypothesis regarding the direct influence of ABA on the level of LTPs in the salt-stressed root cells.

The pattern of shikimate pathway and phenylpropanoids after inhibition by glyphosate or quinate feeding in pea roots

The shikimate pathway is a metabolic route for the biosynthesis of aromatic amino acids (AAAs) (i.e. phenylalanine, tyrosine, and tryptophan). A key enzyme of shikimate pathway (5-enolpyruvylshikimate-3-phosphate synthase, EPSPS) is the target of the widely used herbicide glyphosate. Quinate is a compound synthesized in plants through a side branch of the shikimate pathway. Glyphosate provokes quinate accumulation and exogenous quinate application to plants shows a potential role of quinate in the toxicity of the herbicide glyphosate. Based on this, we hypothesized that the role of quinate accumulation in the toxicity of the glyphosate would be mediated by a deregulation of the shikimate pathway. In this study the effect of the glyphosate and of the exogenous quinate was evaluated in roots of pea plants by analyzing the time course of a full metabolic map of several metabolites of shikimate and phenylpropanoid pathways. Glyphosate application induced an increase of the 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS, first enzyme of the shikimate pathway) protein and accumulation of metabolites upstream of the enzyme EPSPS. No common effects on the metabolites and regulation of shikimate pathway were detected between quinate and glyphosate treatments, supporting that the importance of quinate in the mode of action of glyphosate is not mediated by a common alteration of the regulation of the shikimate pathway. Contrary to glyphosate, the exogenous quinate supplied was probably incorporated into the main trunk from the branch pathway and accumulated in the final products, such as lignin, concomitant with a decrease in the amount of DAHPS protein.

Prohexadione-Ca and coper effect on growth and acumulation of endogenous polyamines in pea plants

Abstract The effect of retardant Prohexadione-Ca (BAS 125 10W, BASF Corp., Germany) and heavy metal copper on growth and endogenous concentrations of free and conjugated putrescine, spermidine and spermine in roots and leaves of pea plants were investigated. It was found that the polyamine concentrations increased seven days after the treatments. Most considerable increase of polyamines was detected in plants treated with copper and Prohexadione-Ca. The variations in polyamine concentrations in leaves and roots of pea plants suggest that Prohexadione-Ca had a protective effect against Cu stress of pea plants, which was expressed by additional accumulation of polyamines.

Reactive oxygen species production and antioxidative defense in pea (Pisum sativum L.) root nodules after short-term aluminum treatment

Pea plants (Pisum sativum L.) were treated with 50 μM aluminum chloride at pH 4.5 for 2 or 24 h at room temperature. Following treatment, root nodule Al uptake, the generation of reactive oxygen species (ROS, O 2 −· and H2O2), and the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and peroxidase (POX) were investigated. Aluminum accumulation was found chiefly in the apoplast of the nodule cortex, endodermis and meristem, while the formation of peroxide was detected in the nodule cortex, infection threads and bacteroidal tissue. Further, there were increased levels of superoxide in the meristem and bacteroidal tissue. The activity of SOD (EC 1.15.1.1) and POX (EC 1.11.1.7) increased in the Al-treated nodules and the roots of pea plants, whereas CAT (EC 1.11.1.6) activity decreased. The Al absorbed by the nodules induced ROS production. The POX and SOD are important ROS-scavengers in Al-stressed nodules.

Provision of carbon skeletons for amide synthesis in non-nodulated soybean and pea roots in response to the source of nitrogen supply

Soluble amino acids in roots and primary amino acids, which were involved in primary ammonium assimilation, in the metabolites of 14C-glucose fed to roots for 3 h in the dark were analyzed in the roots of non-nodulated soybean and pea plants grown in ammonium, nitrate or nitrogen-free media for 1 day. Compared with the effect of nitrate, ammonium supply strongly affected the content and synthesis of the amino acids in the roots. In both soybean and pea roots, the supply of ammonium increased considerably the concentrations of the primary amino acids, and asparagine was the most predominant amide, followed by glutamine. In nitrate-supplied soybean roots, the concentrations of asparagine, aspartate and alanine increased, but the concentration of glutamine was low. In the roots of pea plants grown in nitrate media, asparagine was the predominant amino acid, although the composition of the primary amino acids was little affected by nitrate supply. The proportion of amino acids synthesized from 14C-glucose increased and asparagine rather than glutamine was predominantly synthesized in ammonium-supplied soybean and pea roots, whereas in nitrate-supplied roots asparagine was more actively synthesized than glutamine, although asparagine was not predominant. The ratio of C4 (asparagine + aspartate) to C5 (glutamine + glutamate) amino acids was twofold higher in ammonium-supplied and nitrate-supplied soybean roots than in roots receiving no nitrogen. In contrast, in pea roots, the C4/C5 ratio was twofold higher only in ammonium nutrition. The results obtained suggest that the roots of leguminous plants might possess an indigenous ability to provide a carbon skeleton for preferential synthesis of asparagine rather than glutamine with a high intensity of ammonium supply.

Immunocytochemical localization of Pisum sativum TRXs f and m in non-photosynthetic tissues.

Plants are the organisms containing the most complex multigenic family for thioredoxins (TRX). Several types of TRXs are targeted to chloroplasts, which have been classified into four subgroups: m, f, x, and y. Among them, TRXs f and m were the first plastidial TRXs characterized, and their function as redox modulators of enzymes involved in carbon assimilation in the chloroplast has been well-established. Both TRXs, f and m, were named according to their ability to reduce plastidial fructose-1,6-bisphosphatase (FBPase) and malate dehydrogenase (MDH), respectively. Evidence is presented here based on the immunocytochemistry of the localization of f and m-type TRXs from Pisum sativum in non-photosynthetic tissues. Both TRXs showed a different spatial pattern. Whilst PsTRXm was localized to vascular tissues of all the organs analysed (leaves, stems, and roots), PsTRXf was localized to more specific cells next to xylem vessels and vascular cambium. Heterologous complementation analysis of the yeast mutant EMY63, deficient in both yeast TRXs, by the pea plastidial TRXs suggests that PsTRXm, but not PsTRXf, is involved in the mechanism of reactive oxygen species (ROS) detoxification. In agreement with this function, the PsTRXm gene was induced in roots of pea plants in response to hydrogen peroxide.

The major chemotaxis gene cluster of Rhizobium leguminosarum bv. viciae is essential for competitive nodulation.

Rhizobium leguminosarum biovar viciae strain 3841 is a motile alpha-proteobacterium that can establish a nitrogen-fixing symbiosis within the roots of pea plants. In order to determine the contribution of chemotaxis to the lifestyle of R. leguminosarum, we have characterized the function of two chemotaxis gene clusters (che1 and che2) in controlling motility behaviour. We have found that both chemotaxis gene clusters modulate the motility swimming bias of R. leguminosarum cells and that the che1 cluster is the major pathway controlling swimming bias and chemotaxis. The che2 cluster also contributes to swimming bias, but has a minor effect on chemotaxis. Using competitive nodulation assays, we have demonstrated that a functional che1 cluster, but not the che2 cluster, promotes competitive nodulation of the peas. This finding implies that the environmental cue(s) triggering chemotaxis of R. leguminosarum bv. viciae cells towards the roots of pea and facilitating colonization are likely to be processed through the che1 cluster despite the contribution of both che clusters to swimming behaviour. A phylogenetic analysis of the distribution of che1 and che2 orthologues in the alpha-proteobacteria together with our results allow us to propose that che1 homologues are major controllers of chemotaxis and host association in the Rhizobiaceae.

Short-term ammonium supply stimulates glutamate dehydrogenase activity and alternative pathway respiration in roots of pea plants

The changes of C and N metabolism after switching Pisum sativum L. plants from nitrate to ammonium were studied. Pea plants were grown for three weeks in nutrient solution containing 0.5 mmol/L nitrate, and then randomly divided into five sets for five different nitrogen treatments: control (0.5 mmol/L nitrate) and four ammonium concentrations (0.5, 1, 2.5 and 5 mmol/L). After 72 hours, activities of enzymes related to C and N metabolism were measured. Ammonium content in roots increased with ammonium concentration showing saturation from a concentration of 2.5 mmol/L. Increasing external ammonium concentration also increased free amino acid content (mainly glutamine and asparagine), whereas starch content decreased and neither organic acid or soluble carbohydrates changed. Glutamine synthetase (GS; EC 6.3.1.2) activity decreased and root glutamate dehydrogenase (GDH; EC 1.4.1.2) activity increased with ammonium regardless of the concentration used. Root respiration rate increased with ammonium, due mainly to an increase of the alternative pathway. These results could be consistent with the assumption of a possible role for GDH in ammonium detoxification. Our results show a close relationship between GDH activity and respiration rate through alternate pathways in order to ensure the supply of C skeletons for ammonium assimilation, whereas surplus NADH is oxidised directly via the non-phosphorylating route.

Application of capillary electrophoresis on the characterization of cadmium‐induced polypeptides in roots of pea plants

Capillary electrophoresis (CE) has revealed as a powerful technique for a rapid and effective evaluation of the synthesis of polypeptides induced by cadmium (Cd) in root tissues of Cd‐resistant pea plant. CE was performed on root extracts in capillary gel electrophoresis (CGE) using 3% PEG 2November 1998 in Tris‐Tricine buffer as a dynamic sieving polymer solution and in free solution (FSCE) with 0.1M Tris‐Tricine at pH 8.3 as running buffer. By comparison with control, CGE electropherograms of root extracts of Cd‐resistantpea showed a new peak, characteristic of newly synthesized polypeptidic fraction with apparent molecular weight of 10 kDa. In order to get more information, we characterized further the new synthesized polypeptidic fraction as charge to size ratios. Results obtained by FSCE in free solutions showed that polypeptidic fraction split into several components with different charge to size ratios, very close to that of glutathione, the starting molecule for the biosynthesis of phytochelatins. In addition, results suggested a co‐occurrence of MT‐like proteins at low molecular weight and phytochelatins.

Synthesis of Phytochelatins and Homo-Phytochelatins in Pisum sativum L.

In the roots of pea plants (Pisum sativum L.) cultivated with 20 [mu]M CdCl2 for 3 d, synthesis of phytochelatins [PCs or ([gamma]EC)nG, where [gamma]EC is [gamma]glutamylcysteine and G is glycine] and homophytochelatins [h-PCs, ([gamma]EC)n[beta]-alanine] is accompanied by a drastic decrease in glutathione (GSH) content, but an increase in homoglutathione (h-GSH) content. In contrast, the in vitro activity of GSH synthetase increases 5-fold, whereas h-GSH synthetase activity increases regardless of Cd exposure. The consititutive enzyme PC synthase, which catalyzes the transfer of the [gamma]-EC moiety of GSH to an acceptor GSH molecule thus producing ([gamma]EC)2G, is activated by heavy metals, with Cd and Cu being strong activators and Zn being a very poor activator. Using h-GSH or hm-GSH for substrate, the synthesis rate of([gamma]EC)2[beta]-alanine and [gamma]EC)2-serine is only 2.4 and 0.3%, respectively, of the sythesis rate of ([gamma]EC)2G with GSH as substrate. However, in the presence of a constant GSH level, increasing the concentration of h-GSH or hm-GSH results in increased synthesis of ([gamma]EC)2[beta]-alanine or ([gamma]EC)2-serine, respecively; simultaneously, the synthesis of ([gamma]EC)2G is inhibited. [gamma]EC is not a substrate of PC synthase. These results are best explained by assuming that PC synthase has a [gamma]EC donor binding site, which is very specific for GSH, and a [gamma]EC acceptor binding site, which is less specific and accepts several tripeptides, namely GSH, h-GSH, and hm-GSH.

Relationships between nodulation and auxin level in pea roots

In the roots of 4-day-old pea plants germinated in unsterile soil from Rhizobium-inoculated seeds, a higher level of native IAA was determined than in roots of pea plants germinated in sterile soil from superficially sterilized seeds. The IAA level in plants grown from inoculated seeds increased markedly up to the age of 6 days of the plant, while in plants growing under sterile conditions it did not significantly change during the same period. Between the 6th and 10th days of the age of the plant, a decline in the IAA level was observed in roots of plante growing from inoculated seeds. It was not until after 10 days of age of the plant that the level of IAA in nodulated roots again increased.

Effects of Kinetin and Proline on Enzyme Activities in Roots of Waterlogged Pisum sativum Plants

Flooding greatly enhanced the activity of ADH and GPT in roots of pea plants. An increase was also noted in ethanol content, but malate and proline content remained unaffected. Glutamic acid content, on the other hand, doubled, and glycine and phenylalanine content decreased to half that of the control. The roots of flooded plants evolved 2.4 times more ethylene than the control plants. Treatment of waterlogged plants with kinetin relieved most of the effects of flooding on enzyme activity and ethanol content. Proline promoted the activity of GLDH, but significantly brought down the activities of ADH and GPT. Aeration of the flooded plants also resulted in the normalisation of most of the metabolic processes. The results indicate that both kinetin and proline can, to a very great extent, mitigate the metabolic effects of flooding in pea roots.