Mature Pea Research Articles

Changes in the activities of ferredoxin- and NADH-glutamate synthase during seedling development of peas

Ferredoxin-glutamate synthase (EC 1.4.7.1) and NADH-glutamate synthase (EC 1.4.1.14) activities in pea seedlings (Pisum sativum L., cv. Alaska) were measured during germination and the early stages of growth. Both enzymes were detected at all stages in the developing roots and shoots, but their relative activities varied according to the growth stages. In shoots of 5-d-old seedlings, the ratio of the NADH-enzyme to the ferredoxin-enzyme was 72:28. However, the ferredoxin-activity increased rapidly and in shoots of 17-d-old seedlings, the activities were in the ratio of 3:97. Similar trends in these ratio changes were observed in the roots. In both tissues, the NADH-enzyme was shown to be predominant in the immature parts. When chloroplasts prepared from mature pea leaves were incubated with [(14)C]glutamine and 2-oxoglutarate, the production of [(14)C]glutamate was found to be light dependent and was inhibited by azaserine (3 mM) and 3-(3,4-dichlorophenyl)-1-1-dimethylurea (20 μM). In contrast, considerable amounts of [(14)C]glutamate were formed by chloroplasts from young leaves even in the dark. Addition of malate or dihydroxyacetone phosphate to the reaction mixture resulted in a twofold increase of this dark- and azaserine-sensitive [(14)C]glutamate formation.

Nutritional Quality of Vegetable Crops as Affected by Phosphorus and Zinc Fertilizers1

AbstractThe nutritional quality as well as the yield of the portions of vegetable plants used for human consumption should be considered in fertilization programs.The purpose of this study was to Determine the effects of rates of concentrated superphosphate and zinc sources on some nutritionally important factors including the concentration of P, Zn, phytic acid (myoinositol hexaphosphoric acid), and oxalic acid in the edible portions of four vegetables. The plants, pea (Pisum sativum L.), snap bean [Phaseolus vulgaris (L.) var. humilis], cabbage (Brassica oleracea var. capitata), and table beet (Beta vulgaris L.) were grown on a Honeoye fine sandy loam (Glossoboric Rapludalf, fine loamy, mixed mesic) derived from calcareous glacial till. These crops were fertilized with concentrated superphosphate (CSP) at rates of 0, 30, 60, and 120 kg P/ha, and ZnSO4 or ZnCl2 at rates of 0, 5, 20, and 80 kg Zn/ha applied in a band at planting time in a factorially designed experiment. The plants were sampled at processing stage except that pea and snap bean seeds were also sampled at full maturity. Increasing fertilizer CSP rates increased yields and P concentrations in all crops. Fertilizer CSP increased phytic acid concentrations in immature and mature pea seeds and in mature snap bean seeds. Oxalic acid concentrations in table beet plants decreased with increasing rates of CSP fertilizer. Fertilizer CSP without Zn fertilizer decreased Zn concentrations in the plants, but CSP with Zn fertilizer generally increased Zn concentrations. Fertilizer Zn did not affect yields nor cause visible plant toxicities. However, Zn fertilizer increased Zn concentrations in the plants, especially when applied with high rates of CSP fertilizer. Thus, CSP fertilization without Zn fertilization of vegetable crops can reduce their nutritional quality by lowering their Zn concentrations. However, the concomitant use of Zn fertilizer, with high rates of CSP fertilization, can improve the nutritional quality of vegetable crops with respect to Zn.

Characterisation of the storage protein subunits synthesised in vitro by polyribosomes and RNA from developing pea (Pisum sativum L.)

Evidence is presented to show that legumin, the major storage protein in Pisum, is synthesised in vitro by the wheat germ and reticulocyte lysate systems, from polyribosomes and mRNA isolated from developing pea seeds. While legumin isolated from mature pea seeds consists of 40,000 and 20,000 MW subunits, the in vitro legumin is synthesised as a 60,000 MW precursor consisting of covalently linked 40,000 and 20,000 MW subunits. The implications of these findings are discussed in relationship to studies with other systems.

Cotyledonary Storage Proteins in Pisum sativum. V. Further Studies on Molecular Heterogeneity in the Vicilin Series of Holoproteins

The cotyledonary storage proteins of mature pea seeds were resolved by polyacrylamide gel electrophoresis in an acid buffer system as discrete bands comprising holoproteins referable to either the legumin or vicilin series. Three major and four less abundant vicilin holoproteins were detected in acid-gel separations after subfractionation of storage-protein extracts on the basis of differential solubility at specific pH values and ionic strengths, by electrophoresis in the alkaline pH range or by gel filtration. Acid-gel patterns were qualitatively consistent over a range of genotypes. Up to 12 polypeptides were found in varying proportions in reduced and dissociated eluates from fixed and stained vicilin bands separated on acid gels. Each vicilin holoprotein showed a distinctive quantitative, and in some cases qualitative, polypeptide composition. Genetically determined size or charge variants of certain polypeptides used as markers were found in each of the major vicilin holoproteins. This observation, and the consistent appearance of the vicilin bands on acid gels after exposure to widely different treatments during subfractionation, indicate that these polypeptides are strictly subunits of the vicilins, rather than fortuitously associated components. Amongst the holoproteins of each band, some flexibility of subunit composition is indicated by evidence that the total of the molecular weights of the subunits exceeds the molecular weight of the corresponding holoprotein, and by the apparent relative abundance of certain subunits. The observed complexity of subunit composition of the vicilins is consistent with previous findings of immunological similarities and differences amongst the holoproteins of this series, and with change during development in the subunit composition of these proteins.

Cotyledonary Storage Proteins in Pisum sativum. III. Patterns of Accumulation During Development

An antiserum raised against proteins from isolated protein bodies of mature pea seeds recognized seven antigenically distinct protein families in cotyledon extracts analysed by crossed immunoelectrophoresis. This antiserum has been used to follow the sequence of appearance and pattern of accumulation of these proteins in peas grown under controlled environmental conditions. One antigen present in mature cotyledons was shown to be a haemagglutinin, one corresponded to legumin, and four distinct, non-crossreacting antigenic species were related to the vicilin series of proteins. Both the number of components detected and the order of their appearance during development were similar in three genotypes examined, but the quantitative representation of legumin relative to other components was genotype-specific. Quantitative differences were observed in the polypeptide composition of the vicilin components responsible for separate antigenic specificities, but qualitative differences were not excluded. During development, similar conspicuous quantitative changes in polypeptide composition, accompanied by a change in mean electrophoretic mobility, occurred amongst the molecules carrying the predominant antigenic determinant related to vicilin (peak 4); again, qualitative differences might also distinguish these components. The antigen responsible for peak 6 contained two major polypeptides distinct from the components of the legumin and vicilin fractions. Peak 6 represented the first fully immunocompetent species to appear during development, but later became quantitatively less significant as the other antigenic species accumuIated. Legumin and the antigen forming peak 6 were first detected immunologically in an apparently incomplete form. These putative precursors disappeared during subsequent development, so that only the corresponding stable precipitin peaks were seen in the immunoelectrophoretic profiles of extracts from mature cotyledons.

18 ?m replication units of chromosomal DNA fibers of differentiated cells of Pea (Pisum sativum)

Explants of stelar and cortical mature pea root tissues were cultured on solid agar synthetic medium for up to 6 d. On the 3rd and 6th day the tissue was pulsed with 3H-thymidine from 15 up to 180 min to label the DNA. Subsequently the nuclei were isolated, lysed, and the DNA spread on microscope slides. The autoradiograms of labeled DNA fibers showed that the average replication fork traveled at 9 μm/h, and that an average of 18 μm of DNA separated activated origins. Nearly identical parameters were obtained from DNA of all callus independent of tissue source and independent of the presence or absence of kinetin in the medium.

Further studies on the metabolism of gibberellins (GAs) A9, A20 and A29 in immature seeds of Pisum sativum cv. progress No. 9

Seed maturation of Pisum sativum cv. Progress No. 9 proceeds more slowly in winter than in summer even when the parent plants are grown in greenhouse conditions with light-and heat-supplementation. For parent plants grown under "summer" and "winter" conditions the metabolism of [(3)H]GA9 in cultured seeds is qualitatively different in seeds of equivalent age and qualitatively the same in seeds of equivalent weight. 13-Hydroxylation of [(3)H]GA9→[(3)H]GA20 is restricted to early stages of seed development. 2β-Hydroxylation of [(3)H]GA9→2β-OH-[(3)H]GA9 has only been observed at a stage of development after endogenous GA9 has accumulated. 2β-OH-GA9 has been shown to be endogenous to pea and is named GA51. H2-GA31 and its conjugate have not been shown to be present in pea and may be induced metabolites of [(3)H]GA9. The metabolism of GA20→GA29 is used to illustrate a technique of feeding [(2)H][(3)H]GAs in order to distinguish a metabolite from the same endogenous compound. The in vitro conversion of [(3)H]GA20→[(3)H]GA29, and the virtual non-metabolism of [(3)H]GA29 have been confirmed for seeds in intact fruits. These results are discussed in relation to the apparent absence of conjugated GAs in mature pea seeds.

Effects of cations upon chloroplast membrane subunit. Interactions and excitation energy distribution.

When isolated chloroplasts from mature pea (Pisum sativum) leaves were treated with digitonin under "low salt" conditions, the membranes were extensively solubilized into small subunits (as evidenced by analysis with small pore ultrafilters). From this solubilized preparation, a photochemically inactive chlorophyll - protein complex (chlorophyll alpha/beta ratio, 1.3) was isolated. We suggest that the detergent-derived membrane fragment from mature membranes is a structural complex within the membrane which contains the light-harvesting chlorophyll alpha/beta protein and which acts as a light-harvesting antenna primarily for Photosystem II. Cations dramatically alter the structural interaction of the light-harvesting complex with the photochemically active system II complex. This interaction has been measured by determining the amount of protein-bound chlorophyll beta and Photosystem II activity which can be released into dispersed subunits by digitonin treatment of chloroplast lamellae. When cations are present to cause interaction between the Photosystem II complex and the light-harvesting pigment - protein, the combined complexes pellet as a "heavy" membranous fraction during differential centrifugation of detergent treated lamellae. In the absence of cations, the two complexes dissociate and can be isolated in a "light" submembrane preparation from which the light-harvesting complex can be purified by sucrose gradient centrifugation. Cation effects on excitation energy distribution between Photosystems I and II have been monitored by following Photosystem II fluorescence changes under chloroplast incubation conditions identical to those used for detergent treatment (with the exception of chlorophyll concentration differences and omission of detergents). The cation dependency of the pigment - protein complex and Photosystem II reaction center interactions measured by detergent fractionation, and regulation of excitation energy distribution as measured by fluorescence changes, were identical. We conclude that changes in substructural organization of intact membranes, involving cation induced changes in the interaction of intramembranous subunits, are the primary factors regulating the distribution of excitation energy between Photosystems II and I.

Lipid biosynthesis by isolated plastids from greening pea, Pisum sativum

Isolated etioplasts from 8-day-old dark-grown pea seedlings incorporated [1-(14)C]acetate into lipid at a relatively low rate. Plastids from seedlings that had been illuminated for at least 2 hr showed an enhanced incorporation provided the plastids were illuminated during incubation with the labeled acetate. Dark incubation or the addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) decreased the acetate-incorporating activity of the developing chloroplasts to the level observed with etioplasts. Light had a marked effect on the type of fatty acid into which acetate was incorporated by the developing chloroplasts. Unsaturated fatty acids (mostly oleic acid) accounted for 60-80% of the incorporated label if the plastids were illuminated, but in the dark or in the presence of DCMU the unsaturated acids accounted for only 0-15% of the label incorporated into lipid. The effect of ATP on incorporation was dependent on the maturity of the chloroplasts; mature pea chloroplasts were inhibited by ATP, whereas in developing plastids there was a slight stimulation by ATP. Inhibition of acetate incorporation into lipid by DCMU appears to be due to inhibition of noncyclic phosphorylation. Incorporation was restored by reduced 2,3,5,6-tetramethylphenylenediamine, which restored phosphorylation, but not by reduced N,N,N',N'-tetramethylphenylenediamine.

Protein Synthesis in Cotyledons of Pisum sativum L

The changes in protein content of pea cotyledons have been followed during the period from 9 to 33 days after flowering. Initially protein content increased gradually with a rapid period of deposition occurring between days 21 and 27 after flowering. After the 28th day the rate of accumulation of protein declined as the seed dehydrated and matured. At maturity the pea cotyledon contained approximately 25% protein which was divided into albumins and globulins in the ratio of 1:1.4.Analytical data and the incorporation of exogenously supplied (14)C-leucine indicated that albumins were synthesized early in cotyledon development whereas globulin synthesis predominated with increasing maturity.Ribosomal preparations extracted from seeds during the period of rapid protein synthesis contained a high percentage of polysomes. Preparations from older cotyledons with a declining capacity for protein synthesis had few polysomes and an abundance of monosomes. The amino acid-incorporating capacity of ribosomal preparations from cotyledons of varying age was related to the polysomic content. The phenylalanine-incorporating capacity of ribosomal preparations from mature pea seed could be stimulated by the addition of polyuridylic acid. The distribution of polysomes and the in vitro incorporation data suggested that protein synthesis could be partially restricted by the availability of messenger RNA at maturity.However, reciprocal mixing experiments of supernatant and ribosomal fractions from cotyledons of different developmental age indicated that the supernatant fractions have varying capacities to stimulate in vitro amino acid incorporation. Thus the possibility of the regulation of protein synthesis at the translational level was not precluded.

The Identification of Main Proteins Fractions from Pea Protein Isolates

Pea’s proteins represent a valuable source of edible proteins which are well tolerating by human body, and contain all essential amino acids. Mature pea’s seeds are very rich in proteins that can be extracted in order to be used to improve the nutritional value of other foods.
 Pea’s proteins contain several fractions of albumins and globulins. We have used electrophoresis to separate and identify these fractions, to establish the molecular weight of each fraction, and also the proportion between them. The electrophoresis was conducted following the SDS-PAGE protocol.
 Using pea protein isolate as sample, we have found a number of 12 protein fractions with molecular weights ranging between 12500 and 140000 Daltons. From these, six fractions are prevalent.

The rôle of the host plant in the production of winged forms by two strains of the pea aphid, Acyrthosiphon pisum

Aphids of both strains of Acyrthosiphon pisum can produce alate daughters after experiencing a controlled period of contact with other aphids. This response is maternal, embryos being irrevocably determined as apterae or alatae very shortly before birth. Females of the green strain crowded soon after the onset of parturition did not produce many alate offspring when reared exclusively on seedlings of the bean Vicia faba. When the insects fed on mature bean leaves after the 24 hr crowding treatment the proportion of alatae in their progenies was more than doubled. Besides being influenced by the diet imbibed after the crowding experience, the maternal response was conditioned by the host plant offered the test insects during their larval development. Bean seedling host plants decreased the proportion of alatae subsequently produced, while mature bean leaves had the reverse effect. The production of numerous alatae in response to the combined influence of crowding and a mature leaf host was rapidly halted when the parent aphids were transferred to bean seedlings. Often all larvae subsequently deposited became apterae. Aphids of the pink strain studied here were particularly sensitive to contact with other aphids, and readily produced large numbers of alatae even when feeding on bean seedlings. Nevertheless, more alatae appeared in the progenies of crowded females caged on mature bean leaves. Females of both strains reared singly on bean seedlings prior to the onset of parturition started to deposit alate daughters within 72 hr of being transferred without crowding to mature leaves. Progressively greater numbers of these forms were produced as larviposition continued. This response appeared earlier in the case of females reared singly on mature leaves from birth onwards. Two varieties of the pea Pisum sativum had a particularly pronounced effect on alata-production by females of the green strain. Regardless of whether the aphids imbibed sap from pea seedlings before or after a crowding treatment, the majority produced no alate progeny whatsoever. The response of the pink aphids was not as easily influenced by this factor. When previously crowded apterae of the green strain reproduced on mature pea leaves, a response developed of comparable intensity to that of insects confined on bean seedlings. Fewer alatae were produced by females caged on excised mature pea leaves fed with glucose and amino acids than on leaves fed with a pure glucose solution.

GENOTYPE RECOGNITION IN PEAS BY WATER IMBIBITION OF SEEDS

Significant differences in the water absorption capacity of mature pea seeds were found between lines or varieties within and between each of four genetically different seed types, round, wrinkled, "new" wrinkled, and "double" wrinkled. The differences in water absorption were positively correlated with sugar content of immature peas. They were also negatively correlated with seed weight in lines with the genes for new wrinkled.Peas with both classical (rr) and the genes for new wrinkled have high water absorption indices and small seeds. Immature seeds contain from 14.6 to 17.0% sugar or about 1% more than classical wrinkled varieties.

Dealkylation of Atrazine in Mature Pea Plants

Dealkylation of Atrazine in Mature Pea Plants

OCCURRENCE AND PROPERTIES OF L-AMINOACID:2-GLYOXYLATE AMINOTRANSFERASE IN PLANTS

Extracts prepared from a variety of higher plant tissues have been examined for L-aminoacid:2-glyoxylate aminotransferase (glyoxylate transaminase) activity. This enzyme has been detected in extracts prepared from sunflower cotyledons, corn coleoptiles, mature pea leaves, and carrot storage tissues.Measurement of glyoxylate transaminase activity was based on ability of the extracts to convert glyoxylate- 1,2-C14 to glycine-1,2-C14 in the presence of a suitable amino group donor.Properties of this enzyme system, including amino donor requirements, inhibition, pH optima, and reversibility, have been studied using extracts prepared from mature pea leaves. In sunflower cotyledons, glyoxylate transaminase activity decreased during germination. Studies of the intracellular localization of this enzyme have shown that glyoxylate transamination occurs mainly in the cytoplasm.

The acid-soluble nucleotides of mature pea seeds.

Research Article| December 01 1962 The acid-soluble nucleotides of mature pea seeds EG BROWN EG BROWN Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1962) 85 (3): 633–640. https://doi.org/10.1042/bj0850633 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share MailTo Twitter LinkedIn Cite Icon Cite Get Permissions Citation EG BROWN; The acid-soluble nucleotides of mature pea seeds. Biochem J 1 December 1962; 85 (3): 633–640. doi: https://doi.org/10.1042/bj0850633 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1962 The Biochemical Society1962 Article PDF first page preview Close Modal You do not currently have access to this content.

Kinetin, as a mitotic stimulant in Triturus viridescens.

MILLER et al.1–3 presented evidence that kinetin when used together with indolyl-3-acetic acid increased cell proliferation in tobacco callus tissue. These authors isolated kinetin from the DNA of herring sperm and calf thymus. Since that time additional evidence indicating that kinetin acts as a mitotic stimulant on plant tissues has been presented. Guttman4 reported a larger proportion of division figures in the meristematic region of roots of Allium cepa following 4 and 24 hr. treatment with kinetin. Torrey5 noted that kinetin together with 2,4-D initiated frequent mitoses in tetraploid muclei in excised callus tissue from mature pea roots. In the absence of kinetin the tetraploid nuclei remained in the resting state. The action of kinetin on animal tissues is still controversial. Cudkowicz6 treated mice with kinetin following irradiation and compared these with mice that were simply irradiated. He noted that irradiation inhibited mitoses in the crypts of Lieberkuhn. The return to the normal mitotic rate was enhanced by treating the mice with kinetin following irradiation.

Kinetin as trigger for mitosis in mature endomitotic plant cells

Pea root callus tissue cultivated for many months on a nutrient medium containing yeast extract and the auxin, 2,4-dichlorophenoxyacetic acid, is predominantly composed of dividing cells of the tetraploid chromosome number even though the initial tissues cultured from the root were known to consist in part of cells of the diploid chromosome number. In experiments designed to determine the basis for what appeared to be cell selection by the nutrient medium, 1-mm thick segments of 60 hr germinating seedling roots of the garden pea, Pisum sativum, excised 10–11 mm behind the root tip, were cultivated on a synthetic nutrient medium in which the yeast extract was replaced by a mixture of vitamins, amino acids, amides and urea. On such a medium, callus tissues developed, but only diploid cell mitoses were observed. Upon the addition of 1 ppm kinetin (6-furfurylaminopurine) to the synthetic medium, the number of cells in mitosis approximately doubled and a very high percentage of dividing cells possessed the tetraploid chromosome number. Lower concentrations of kinetin were proportionately less effective in stimulating mitosis and in bringing tetraploid cells into mitosis. From these studies it has been concluded that kinetin specifically triggers mitosis in mature pea root tissue cells which have undergone DNA- and chromosome-doubling by endomitotic reduplication before kinetin treatment. This conclusion is based on the following lines of evidence: ( a) After 2 days of kinetin treatment, the tetraploid cells which enter mitosis showed diplochromosomes, indicating that chromosome doubling had been endomitotic; ( b) Tetraploid mitoses were largely localized in mature cortical cells of the root while most diploid mitoses occurred in tissues of the central cylinder; ( c) One-mm root tips cultured for up to 7 days in 1 ppm kinetin showed no tetraploid mitoses, which is expected since few or no endomitotically doubled cells are likely to occur in the apical meristem of the root. Certain experiments in which adenine sulfate or adenosine was fed the mature pea root segments together with kinetin suggest that an interaction between adenine and kinetin does occur in which adenine reverses in part the effect of kinetin on induction of mitoses in mature endomitotic cells.

The Effect of High Oxygen Pressure on the Respiratory Metabolism of Pea Seeds

The time course of the changes in concentration of certain of the intermediates of the Krebs cycle (and derivatives of these intermediates) in the mature pea seed during the inhibition of respiration by high oxygen pressure has been studied. The results support the conclusion that the primary effect of high oxygen pressure is an inhibition of the oxidation of citric acid by the Krebs cycle. Aconitase appears to be the most likely site of inhibition. In the later stages of treatment there appears to be a slowing of the rate of glycolysis either as a consequence of the primary inhibition or due to direct inhibition of other enzymes. The highest rate of citrate accumulation observed in this work would allow 50 per cent, of the aerobic carbon dioxide output of the pea seed to be derived from the Krebs cycle.

Triosephosphate dehydrogenase and glucose-6-phosphate dehydrogenase in the pea plant.

THERE is considerable evidence indicating that the mechanisms of carbohydrate catabolism are the same in higher plants, yeast and muscle1. However, it has been reported that mature pea plants do not oxidize triosephosphate2.