Immunochemical behaviour of legumin and vicilin from Vicia faba: a survey of related Proteins in the leguminosae subfamily faboideae

An antiserum specific for the legumin and vicilin of Vicia faba was used to examine extracts of seeds of taxa of the Fabeae and Trifolieae for the presence of related storage proteins, Proteins related to legumin were found to be widely distributed, indicating considerable conservation of the genetic information for this protein. Only Pisum sativum contained a protein immunochemically identical with the vicilin of V. faba; the equivalent proteins of all other genera tested here were immunochemically different from vicilin.     

In Vitro Biosynthesis of Vicia faba Polyphenoloxidase

Poly A⁺ mRNA was isolated from Vicia faba leaves and translated in vitro using a rabbit reticulocyte translation system. From analysis of the total translation products, the major proteins synthesized in vitro were 32 kilodaltons and 20 kilodaltons. When antibodies to Vicia faba polyphenoloxidase were added, a specific immunoprecipitable protein was observed. This protein's molecular weight was shown to be similar to that of the isolated enzyme (45 kilodaltons). The isolated enzyme successfully competed with the in vitro synthesized product for antipolyphenoloxidase. In addition, the in vitro synthesized product was not immunoprecipitated with antitomato peroxidase and comigrated with isolated and/or iodinated enzyme in sodium dodecylsulfate-polyacrylamide gel electrophoresis. Using in vitro translation and specific immunoprecipitation, a primary translation product corresponding to Vicia faba polyphenoloxidase was identified as a 45 kilodaltons protein.     

Expression of human cytomegalovirus pp150 gene in transgenic Vicia faba L. and immunogenicity of pp150 protein in mice

The pp150 gene of human cytomegalovirus (HCMV) was transferred into Vicia faba plants by Agrobacterium tumefaciens-mediated transformation. Three of five hygromycin resistant V. faba plants were identified as positive by PCR and dot-blot hybridization. The ELISA results indicated that pp150 protein from three plants of transformed V. faba leaves and seeds made up 0.005–0.015% of the total soluble protein. The results of detection by immunoblot and inhibition of immunofluorescent assay (IFA) showed that pp150 soluble protein had immunity activity. HCMV pp150-specific antibody (IgG, IgA) and IFN-γ producing T cells were detected in 100% of the mice immunized with pp150 transgenic V. faba seeds by ELISA and intracellular staining and flow cytometry analysis, respectively. The transgenic V. faba plants will provide new material for the development of edible vaccination against HCMV infection.     

Comparative electrophoretical analysis of plasmid-like mitochondrial DNAs in Vicia faba and in some other legumes

Minicircular DNAs found in mitochondria of 6-d-old etiolated seedlings of Vicia faba L. were also present in mitochondria isolated from cell suspension cultures and from green leaves of this plant. These results support the suggestion that the plasmid-like molecules found in mitochondria of V. faba are an essential component of the mitochondrial genome. The minicircular DNAs were, apparently, peculiar for the species V. faba since they were found in all three cultivars of this species which were studied. The distribution pattern of plasmid-like DNAs in Vicia villosa L. was completely different and mitochondria from Medicago sativa L. also contained specific minicircular DNAs. Thus, minicircular DNAs are typical for the mitochondrial genomes of several legumes and different plant species have their specific mitochondrial plasmid-like DNAs     

Plant extracts induce chromosome aberrations and sister-chromatid exchanges in Chinese hamster ovary cells and human lymphocytes

Effects of extracts from Vicia faba were compared with those of Zea mays for the induction of sister-chromatid exchanges (SCEs) and of chromosome aberrations (CAs) in Chinese hamster ovary (CHO) cells. CA induction by the maize extract was also tested in human lymphocytes. The extracts from roots and leaves of Vicia faba induced CAs and SCEs in CHO cells. The extracts from maize leaves also induced SCEs and CAs in CHO cells, and CAs in human lymphocytes. Maize extracts were more potent in inducing SCEs than Vicia extracts and the SCE- and CA-inducing capacity of maize extracts decreased during preincubation before addition to cells.     

Characterisation and serology of virus-like particles associated with faba bean necrotic yellows

A disease showing chlorosis, leaf rolling and stunting in Vicia faba and other legumes was observed in West Asia and North Africa during 1987–1988. The putative causal agent could not be transmitted mechanically, but could be transmitted by aphids, most efficiently by Acyrthosiphon pisum, in the persistent manner. Further studies revealed isometric virus-like particles (VLPs) closely associated with the disease, although their infectivity could not be demonstrated by membrane feeding. These particles, measuring c. 18 nm in diameter and containing a capsid protein of about 22 kDa and ssDNA of about 1 kb, are hereafter designated faba bean necrotic yellows virus (FBNYV). A high proportion of circular nucleic acid molecules of about 0.9 kb were visualised by electron microscopy. Hybridisation analysis of cloned viral DNA suggests that the circular genome is larger than 1 kb and consists of several components of similar size. An antiserum produced against FBNYV was used in ELISA, immunoelectron microscopy (IEM) and Western blot experiments for virus detection in aphids and field samples and for serological comparison with other viruses. Weak heterologous reactions between FBNYV and subterranean clover stunt virus (SCSV) were detected in IEM, but could not be confirmed in ELISA or Western blots. No serological relationship to banana bunchy top virus (BBTV) was detected. Using a direct tissue blot immunoassay (TBIA), FBNYV was detected in vascular tissue of infected faba bean leaves and stems.     

Studies of Polyclonal Antibodies for the Detection of MLOs Associated with Faba Bean (Vicia faba L.) Using Different ELISA Methods and Dot-blot

Polyclonal antibodies were raised in rabbits against MLO associated with faba bean (Vicia. faba L.) phyllody which exists in the Sudan. Two indirect ELISA methods were able to detect the MLO antigens. In the former, the whole antigen was directly coated onto plates, while in the second, only the F(ab')₂, fragments of the IgG were used to coat the ELISA plates. Higher detectable efficiency was obtained when the F(ab')₂ method was used. Moreover the obtainable antiserum was found to exhibit a high degree of specificity through which the MLO associated with faba bean phyllody in the Sudan, are serologically differentiated from other isolates of MLO existing in the Sudan as well as European MLO isolates maintained at Versailles, and Spiroplasma citri, causal agent of Citrus Stubborn Disease. The positive reactions obtained with this antiserum against MLO phyllody naturally existing in the Sudan on Crotalaria saltiana and some Catharanthus roseus demonstrate that these plants are potential reservoirs of the disease in the Sudan. The same antiserum was used in order to distinguish healthy and diseased plant preparations using the membrane ELISA method (dot-blot).     

On the mechanism of cytoplasmic male sterility in the 447 line of Vicia faba

The trait of cytoplasmic male sterility, expressed in plants bearing the 447 cytoplasm of Vicia faba, is uniquely and positively correlated with the presence of a linear double-stranded RNA molecule (dsRNA) 16.7 kb in size. Restriction enzyme digestion profiles of mitochondrial DNA isolated from fertile and cytoplasmic malesterile (CMS) lines do show a limited number of specific differences in fragment intensities and mobilities. However, mitochondria isolated from the progeny of the cross CMS × Restorer line contain DNA with an identical restriction profile as the male-sterile parent: moreover, subsequent generations are completely and permanently fertile, even upon segregation of the nuclear restoration gene. Southern hybridizations, using cDNA clones as probes, reveal homology between the CMS-associated dsRNA and the nuclear genome of both sterile and fertile lines. The regions cloned, representing approximately 22% of the total dsRNA sequence, show no homology to organelle DNA. We have not been able to stably transmit the dsRNA to fertile lines of V. faba or any other plant species, using a variety of standard virological techniques.     

Absence of DNA repair replication after chemical mutagen damage in Vicia faba

Exposure of human (Hela) cells to the mutagens 4-nitroquinoline-1-oxide (4NQO) and N-methyl-N′-nitro-nitrosoguanidine (MNNG) produces damage in DNA that is repaired by a mechanism involving the insertion of new bases into DNA (repair replication). Vicia faba root tips, either from soaked seeds containing non-proliferating cells or from growing roots, do not perform detectable amounts of repair replication even though the mutagens inhibit DNA synthesis and cause chromosome aberrations. In view of similar failures to resolve excision in Chlamydomonas, Haplopappus, and Nicotiana after irradiation with UV light and in Vicia faba after X-irradiation it appears that plants in general might lack this repair process.     

Nuclear DNA characterization of two species ofVicia:Vicia bithynica L. andVicia narbonensis L.

The speciesVicia bithynica andVicia narbonensis, from the same subgeneric section ofVicia faba, show variations in nuclear DNA content Nuclear DNAs, extracted from root tips of the twoVicia species, were characterized by thermal denaturation, analytical ultracentrifugation and reassociation kinetics. The thermal denaturations of DNA, the number of DNA components reassociating with second order kinetics, the proportion of repeated DNA sequences, the frequency of the repeated DNA classes are reported and compared to previous data onVicia faba DNA. Feulgen absorptions at different thresholds of optical density⁺ of interphase nuclei in cytological preparations of the root meristems ofV. bithynica andV. narbonensis are determined and compared withV. faba analogous determinations. The results, confirming that plant genome is highly flexible, are discussed in relation to other data on the interspecific variations of the nuclear DNA content.     

Histogenesis and localization of non-specific esterase in root tip

A procedure was developed for satisfactory freeze-sectioning of root tips. The use of Ca formol-fixed material kept and frozen in Holt's syrup is recommended. The existence and different localization of 2 fractions of non—specific esterase was verified in root tips ofVicia faba. The same results were revealed in fixed and unfixed material. The dynamics ofin situ reaction was followed with respect to optimal incubation time. The results with substrates of different chain length support the existence of 2 fraction of the studied enzyme, none of which, concerning substrate specificity, is a lipase. It follows from the present studies inVicia faba and other species (Cucurbita pepo, Lupinus albus, Pisum sativum Zea mays), that non-specific esterase localization is not directly given by histogenesis.     

Heavy meromyosin complexing filaments in the phloem of Vicia faba and Xylosma congestum

Summary Stem sections of Vicia faba L. were incubated with rabbit-muscle heavy meromyosin (HMM) and HMM complexes with phloem filaments (P-protein) were observed with the electron microscope. Treatment of sections of Vicia faba and of Xylosma congestum (Lour.) Merr. with fluorescent HMM resulted in a weak fluorescence of the phloem region. Inasmuch as HMM-binding is believed to be specific for actin-like proteins, it is proposed to classify P-protein as such.     

Abscisic Acid Accumulation by in Situ and Isolated Guard Cells of Pisum sativum L. and Vicia faba L. in Relation to Water Stress

Isolated guard cells, prepared by sonication of epidermal peels, were used to investigate the endogenous level of abscisic acid (ABA) in the guard cells of turgid and stressed leaves of Vicia faba L. and the argenteum (arg) mutant of Pisum sativum L. The guard cells of V. faba and arg were found to contain 18 and 8 times more ABA, respectively, when isolated from stressed leaves than from turgid leaves. Isolated guard cells of V. faba were also directly stressed with the osmoticum Aquacide III. These guard cells were capable of producing stress-induced ABA to at least 3 times their ABA level when non-stressed.     

Glucose-6-phosphate dehydrogenase isoenzymes in root growth zones ofVicia faba

The specific activity of glucose-6-phosphate dehydrogenase (G-6-PD) in growth zones ofVicia faba roots is increasing with cell maturation and differentiation. Changes in the total activity of G-6-PD are not associated with a change in the number of G-6-PD isoenzymes. Five G-6-PD isoenzymes were found in all root growth zones. Some differences were found in the activity of individual isoenzymes.     

Structural basis for the affinity of four insolubilized lectins,with a specificity for α-D-mannose,towards various glycopeptides with the N-glycosylamine linkage and related oligosaccharides

Precisions are given on the fine specificity and on the usefulness of immobilized concanavalin A,Lens culinaris, Vicia faba andPisum sativum agglutinins for fractionation of glycopeptides with the N-glycosylamine linkage.While insolubilized concanavalin A represents a very useful tool for the fractionation of both N-acetyllactosaminic and oligomannosidic type glycopeptides or related oligo-saccharides, immobilizedLens culinaris, as well asVicia faba orPisum sativum agglutinins allow the subfractionation of some N-acetyllactosaminic glycopeptide populations on the basis of the presence of an α-L-fucose residue substituting in C-6 position the N-acetylglucosamine residue involved in the N-glycosylamine bond.     

Multiple forms of Vicia faba α-galactosidases and their relationships

Three highly purified α-galactosidases, I, II¹ and II² have been isolated from resting Vicia faba seeds. Form I (MW 160 000) is a tetrame     

STRANDEDNESS OF VICIA FABA CHROMOSOMES AS REVEALED BY ENZYME DIGESTION STUDIES

Chromosomes and nuclei isolated from neutral formalin-fixed Vicia faba lateral roots were treated with trypsin, pepsin, RNase, or DNase. Only trypsin affected the morphology of the chromosomes and nuclei. The appearance of the chromosomes after trypsin digestion indicated that each chromatid contained four strands that could be seen with an ordinary light microscope. The experiments are interpreted as indicating that mitotic chromosomes of Vicia faba are multistranded and that the linear continuity of the chromosome is dependent on protein.     

Die Wirkung von Chloramphencol und Streptomycin auf die Lamellarproteine der Chloroplasten von Vicia faba

Vicia faba plants sprayed with chloramphenicol (0.1%) or streptomycin (0.5%) produce chlorotic chloroplasts with a modified pattern of lamellar proteins. The antibiotics were found to affect the protein patterns by specific inhibition of at least two lamellar proteins. The proteins whose synthesis was found to be inhibited by the antibiotics are evidently produced by the 70S ribosomes of chloroplasts.     

Effects of salt stress on nitrogenase activity and growth of four legumes

The effects of salt stress on nitrogenase (N2-ase) activity, growth and nitrogen content ofVicia faba (L.),Medicago sativa (L.) Merrill,Glycine max andVigna sinensis (L.) were investigated. Four levels of salinity were applied and salt treatments were imposed on inoculated and N-fertilized plants.M. sativa tolerated mild levels of salinity but higher salt concentrations depressed N₂-ase activity of this species. The other three legumes were considerably affected by salt treatments, and N₂-ase activity was significantly reduced by salinity. Vicia faba, carrying elongate nodules, could restore a partial N₂-ase activity upon recovery from salt stress whereasG. max andV. sinesis, both with spherical nodules, could not regain significant activity when salinity was removed. Salt stress retarded growth of both inoculated and N-fertilized plants. The nitrogen content of both treatments was also affected by salinity and the effect was more severe for inoculated than N-fertilized plants.     

Arabinans from the roots of horsebean (Vicia faba)

Young roots from the horsebean (Vicia faba L.) show a very high content of arabinose among their constituent cell-wall carbohydrates. Two water-soluble arabinans have been isolated from the cell-wall material. Their structures have been established by chemical methods and by ¹³C-n.m.r. spectroscopy and showed to consist of an α-(1→5)-linked backbone of l-arabinofuranose residues; arabinopyranose residues are absent. The latter feature make these polysaccharides slightly different from arabinans from other origins that are characterized by their high degree of branching.