Pea Isolates Research Articles

The pathogenicity on legumes of Cucumber mosaic virus was determined by 243 nucleotides on 2a polymerase gene of viral RNA2

We had isolated and identified two Cucumber mosaic virus (CMV) isolates, the CMV red bean (CMV-RB) isolate and the CMV pea (CMV-P1) isolate. CMV-RB induces necrotic local lesions on inoculated leaves of broad bean, pea, cowpea and bean, and could not infect these hosts systemically. However, CMV-P1 was able to infect these legumes systemically. To study the difference of pathogenicity on the legumes induced by these two CMV isolates, the full-length infectious cDNA clones of CMV-Fny, which induced similar symptoms as CMV-RB in the four legumes, were used. The 243 nucleotides fragment, which encodes highly conserved GDD amino acid motif on 2a replicase gene of CMV-Fny RNA2, was replaced with that of CMV-P1. The constructed chimeric virus FP could infect these legumes systemically. The exchange of this region changes the virus symptoms on the legumes, indicating that this 243 nucleotides fragment has major effect on pathogenicity of CMV on the legumes.

Evidence of gene flow between pea and bean pathotypes of Aphanomyces euteiches.

Aphanomyces euteiches is a phenotypically diverse pathogen, but the origins of this diversity are not known. To determine if cross-fertilization occurred between pea and bean pathotypes of A. euteiches, a technique to outcross isolates of A. euteiches was developed. Random amplified polymorphic DNA (RAPD) markers and several phenotypic traits were used to identify F, hybrids. Following 16 matings among isolates of different pathotypes, 4 of 82 germinated oospore isolates were inter-pathotype F, hybrids. Two of the four hybrids were infertile, but two were fertile and used to analyze the inheritance of virulence phenotype, host specificity (pathotype), hyphal growth rate, size of the aplerotic zone, and RAPD markers. As compared with parental pea and bean pathotype isolates, F, hybrids exhibited a pea pathotype and intermediate phenotypes in hyphal growth rate and size of the aplerotic zone. Subsequent self-fertilization of F1 hybrids yielded an F2 population that demonstrated segregation of virulence phenotypes, host specificity, hyphal growth rate, and RAPD markers. The results suggest that this diploid homothallic oomycete is capable of outcrossing and that sexual reproduction may play an important role in the generation of phenotypic variation.

Preparation and characterization of films from pea protein.

The conditions for protein film preparation from an alkaline dispersion of a pea protein isolate were investigated in the presence of polyols as plasticizers. Mechanical and barrier properties of resulting films were studied as a function of protein dispersion conditions, protein and plasticizer concentrations and ratios, chain length of the plasticizer, and pH and composition of the alkaline medium. Neither the mode of protein hydration nor the pea isolate origin had a significant effect on the mechanical properties of pea protein films. However, increasing the plasticizer chain length induced slightly higher surface hydrophobicity but poor mechanical properties. Addition of monoglycerides to film-forming solution allowed a significant improvement of the films during aging. Both tensile strength and surface hydrophobicity increased when ammonium hydroxide was used as protein dispersing agent instead of sodium hydroxide.

Soil amendment effects of rape ( Brassica napus) residues on pea rhizosphere bacteria

Rhizosphere bacteria were isolated from pea ( Pisum sativum) plants grown in soil amended with a green manure of high-glucosinolate rape ( Brassica napus ‘Dwarf Essex’), and from pea plants grown in soil without amendment. Total viable counts of bacteria and fluorescent Psuedomonas spp., and proportionate representation of actinomycetes and Gram-negative bacteria in the pea rhizosphere community were not significantly different for amended and non-amended pea. Carbon substrate utilization patterns obtained from Biolog GN microplates were compared. Rhizosphere isolates from the two treatments, that differed by less than 50% in utilization of specific carbon substrates, were considered to use those substrates in a similar manner. Cluster analysis was used to evaluate relationships of strains according to their abilities to utilize the different carbon substrates. Non-amended pea and amended pea isolates used 88% of the carbon substrates in a similar manner, and cluster patterns were similar for the amended and non-amended pea strains. The number of nodules formed on amended and non-amended pea roots by Rhizobium leguminosarum were not significantly different. Amendment of soil with rape residues did not appear to significantly alter the pea rhizosphere population and community attributes measured.

Physiological Effects of a Pea Protein Isolate in Gnotobiotic Rats: Comparison with a Soybean Isolate and Meat

Pea proteins have been considered for the introduction into the human diet only recently. This protein source was tested on nutritional and digestive parameters in heteroxenic male Fischer rats inoculated with a human faecal microflora from a methane producer. Compared to soybean proteins, pea proteins have similar effects on the rat’s endogenous and bacterial digestive patterns. Compared to the pea proteins, a diet containing a standard meat meal enhanced the pH and the production of ammonia, while a lyophilized beef meat enhanced that of urea. The diet containing the standard meat decreases short-chain fatty acids and modifies the ratio of caecal short-chain fatty acids. Both animal diets decreased the specific activities of pancreatic proteases such as chymotrypsin (EC 3.4.21.1), trypsin (EC 3.4.21.4), and carboxypeptidase A (EC 3.4.17.1) when compared to the diet containing the pea isolate. In conclusion, the whole composition of the diet, more than the origin of the dietary protein, influences the rat’s digestive pattern.

Localization of nod, nif, and acidic exopolysaccharide determinants on a large plasmid in slow-growing cowpea Rhizobium sp. S2.

Slow-growing cowpea Rhizobium sp. S2, a pigeon pea isolate, showed excessive synthesis of exopolysaccharide (EPS) and nod factor(s) only when grown in the presence of corresponding host root exudate (RE) or naringenin (a flavonoid present in RE of pigeon pea). muc- strain, a plasmid-cured derivative of the parent strain, showed negligible EPS production and failed to synthesize the nod factor(s) under similar growth conditions. The nod factor(s) was extracted and partially purified from the total EPS of the culture supernatant of S2 grown in the presence of either RE or naringenin by the butanol-soluble, ethyl acetate-insoluble method. The parent strain also showed ex-planta nitrogenase activity, whereas in muc- it was not detectable. In contrast to observations of the location of nod, nif- and EPS-synthesizing genes on the chromosome in commonly studied cowpea Rhizobia and Bradyrhizobium sp. colony blot and dot blot hybridization studies revealed the presence of nod (common nod genes), nif (nif KDH); and EPS (pss) determinants to be on the large plasmid in the parent strain and therefore absent in muc-, which is a plasmid-cured derivative.

Acetylation of pea isolate in a torus microreactor

Acetylation, which acts on the amino groups of proteins, allows to increase the solubility and the emulsifying properties of pea isolate. Acetylation by acetic anhydride was carried out in a torus microreactor in semibatch and continuous conditions. The mixing characteristics, obtained by a residence time distribution (RTD) method, are the same in batch and continuous processes. The maximum acetylation degree reached by the torus reactor is higher than with the stirred reactor. Torus reactors are more efficient than stirred ones as shown by a conversion efficiency, defined by the quantity of modified lysine groups by consumed acetic anhydride. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 409-414, 1997.

Evaluation of physiological and serological profiles of Pseudomonas syringae pv. pisi for pea blight identification

Phenotypic variability of the pea blight bacterium, Pseudomonas syringae pv. pisi, was studied on a large collection of strains isolated in France, as well as those obtained from foreign collections. Some other pseudomonads encountered on peas, particularly P.s. pv. syringae, were included in the study to evaluate differential tests for identification purposes. All the isolates that induced watersoaking on the pea cultivar Kelvedon Wonder after inoculation were considered to be P.s. pv. pisi. The other pseudomonads gave either no reaction or a hypersensitive reaction. When they corresponded to P. syringae according to the LOPAT test, they were referred to as P.s. pv. syringae. P.s. pv. pisi did not show a single uniform phenotype. The variation of the different tests was estimated (fluorescence+ 93%; esculin‐86%; dl‐lactate‐85%; homoserine + 75%; INA + 97%). Three O‐sero‐groups contained P.s. pv. pisi strains: APT‐PIS (88.5%), HEL2 (11.4%) and RIB (0.1%). When the main criteria were combined, eight profiles were encountered within P.s. pv. pisi. This diversity was not linked to race structure or geographical origin of the strains. Profile PI was the most frequent (72.8%), and it was specific to the pathovar pisi. The strains belonging to the other profiles could be confused with some P.s. pv. syringae strains because of the serological heterogeneity of that pathovar. For instance, the pv. pisi strains belonging to profiles P2 and P4 resembled some of the P.s. pv. syringae found on peas and required pathogenicity tests on pea for their identification. The confusing pea isolates represented 12.8% of the total 4740 strains studied.

Pea and lentil protein extraction and functionality

These studies have demonstrated that peas and lentils can be used as protein sources for flours, concentrates and isolates. Less research attention has been devoted to lentil protein extraction, probably because of the greater cost of lentils as compared to peas. Pin‐milling and air classification is well adapted to extracting pea flours to produce pea protein concentrates. Apparently, air‐classification can be applied successfully to starch rich legumes, but will not give satisfactory results with lipid rich legumes.Wet processes, including alkaline and salt and acid solubilization, together with isoelectric precipitation or ultrafiltration, have been developed. The pea and lentil protein extracts of these processes exhibit comparable and complementary functionality to homologous soybean products. Air‐classified pea protein concentrates are different from soy protein concentrates because of residual starch which can be useful for particular functional applications. Pea isolates appear to exhibit better foaming properties and more solubility than soy isolates, but pea isolates have to be more concentrated than soy isolates to produce viscous dispersions. The economic feasibility of pea and lentil protein extracts is related directly to protein content of the flour, unique functionality of the extracts, marketability of the by‐products of extraction and the cost of peas or lentils.

Specificity of Resistance to Aphanomyces euteiches in Seedling Alfalfa

(...)Resistance to A.e. in experimental populations was not effective against disease caused by Phytophthora megasperma f. medicaginis, and resistance to P. m. f. medicaginis was similarly ineffective against A.e. In another experiment, plants resistant to isolates of A.e. recovered from alfalfa were resistant to isolates from peas. However, pea isolates were less virulent than isolates form alfalfa, even on alfalfa populations previously selected against isolates from pea

The serological relationships and some other properties of isolates of broad bean wilt virus from faba bean and pea in China

SUMMARYAn isolate (N15) of broad bean wilt virus (BB W V) from faba bean in China was compared with some other isolates and strains including the nasturtium ringspot strain (NRSV, BBWV serotype I), parsley virus 3 (PV3, serotype I) and BBWV isolate PV131 (serotype II).In host range studies, N15 infected 12 of 14 species, including soybean and spinach. It was purified from Chenopodium quinoa and pea by a method that yielded up to 8mg/100g tissue. By the same method, NRSV yielded up to 4mg/100 g. Purified preparations of N15 and NRSV contained isometric particles c. 26 nm in diameter which sedimented as three components, N15 at 62, 93 and 117 S, and NRSV at 60, 91 and 116 S.In immunodiffusion tests using antisera to N15 and NRSV, N15 was distinguishable from NRSV but indistinguishable from PV131. In ISEM tests, many more particles of N15 and NRSV were trapped by homologous than by heterologous antiserum; in decoration tests, much antibody attached to homologous particles but none to heterologous particles. In DAS ELISA using N15 antiserum, N15 and six other Chinese faba bean or pea isolates, and a Chinese spinach isolate, were readily detected and were indistinguishable from each other and from PV131; unlike NRSV and PV3, none of the Chinese isolates, nor PV131, was detected using NRSV antiserum. These results indicate that the Chinese isolates belong to BBWV serotype II group.

Emulsifying Properties of Pea Globulins as Related to Their Adsorption Behaviors

ABSTRACTEmulsifying properties of purified pea globulins and of vicilin‐legumin mixtures were evaluated through their emulsifying capacity, emulsifying activity index and stability of the resulting emulsions. The results were discussed by reference to the interface adsorption behaviors of these proteins. The influence of the vicilin/legumin ratio on the efficiency of pea isolates as emulsifying agents was also studied. Vi‐cilin which has been shown to be more surface active at air/water and dodecane/water interfaces, led also, in both cases, alone or mixed, to better emulsifying properties than legumin. The globulin composition of the isolates did not completely explain their emulsifying behaviors.

Three Pea Seedborne Mosaic Virus Pathotypes from Pea and Lentil Germ Plasm

two true leaves expanded and again 1 wk Alconero, R., Provvidenti, R., and Gonsalves, D. 1986. Three pea seedborne mosaic virus later unless otherwise mentioned. pathotypes from pea and lentil germ plasm. Plant Disease 70:783-786. Virus and CIP purification. The method of Yeh and Gonsalves (18) was Three isolates of pea seedborne mosaic virus (PSbMV), P-l and P-4 from pea (Pisum sativum) and used to purify CIP from plants infected L-l from lentil (Lens culinaris) germ plasm accessions, were distinguished by their capacity to infect with isolates P-1 and L-I. The two virus pea genotypes. Resistance in peas was isolate-specific. Resistance to the L-l isolate was associated with bean yellow mosaic virus resistance and also with a delayed reaction to isolate P-4. Several pea isolates were purified according to the germ plasm accessions were resistant to all three isolates. All isolates were infective to 26 genetic method of Dougherty and Hiebert (5) lines of chickpea (Cicer arietinum), a new host, but not to 12 accessions of pigeon pea (Cajanus with some modifications. Infected shoots cajan). Antisera produced against the cytoplasmic inclusion protein induced in peas by P-l and L-I of Ranger pea were harvested and frozen were useful in detecting infections by the indirect ELISA method and were generally more sensitive 24-28 days after inoculation. Tissues than antisera to the viral protein. were homogenized in cold potassium phosphate buffer (0.5M, pH 7.5, with 0.1% Na 2SO 3 and 0.01 M ethyleneGerm plasm collections of pea (Pisum Breeding for resistance to PSbMV in diaminetetraacetic acid) at 2 ml/g of sativum L.) and lentil (Lens culinaris peas may be affected by the kind of plant and carbon tetrachloride at 0.5 ml ofeach Medik.) may not only be reservoirs for response to infection. For example, pea per gram of tissue for an additional pea seedborne mosaic virus (PSbMV) but progenies from certain apparently minute. The homogenate was centrifuged also valuable sources of resistance to this PSbMV-immune parents may show at4. The supentantuwas pathogen (3,10,12,13,17). Resistance in susceptibility to the virus only after a saved, and the pellets were resuspended in pea to the common strain of PSbMV is series of inoculations (11). Likewise, the sa te bf and et rifug ed reported to be conditioned by a single variety of plant responses to PSbMV for 5 min. The combined supernatants recessive gene, designated sbm by infection m ay affect virus eradication were5 cein ifuge atm1,00 g fore5 minnth Hagedorn and Gritton (8). Infection in procedures when slow development of were centrifuged at 1,000 g for 5 mm, the pellets were discarded, and the supernatant this host species may be latent or may be the virus in test plants results in delays in was centrifuged at 10,000 g for 20 mn. At expressed by a wide variety of symptoms detection with bioassay or serological this stage, the pellets contained the ranging from rapid and lethal to delayed methods (2,9). The interaction between cytoplasmic inclusions and the superand transitory (11,15). This variety of PSbMV and pea or lentil becomes more natant ineduthenvirus The viru plant responses in pea has suggested a apparent as we study more representatives precontated by ving The ne modifier-gene system affecting resistance of the host and pathogen. The followin glycol (PEG, mol wt 8,000,4% [w/v] final to this virus (11). Recently, variants of report distinguishes three isolates of concentration) while stirring for 1.5 hr at PSbMV have failed to infect pea cultivars PSbMV by differential responses of pea 4 C. The precipitated virus was collected susceptible to the common strain but genotypes to infection, demonstrates the by centrifugation at 10,000 g for 10 min resistant to bean yellow mosaic virus value of cytoplasmic inclusion protein and resuspended in 40 ml of 0.02 M (BYMV). Gene mo, responsible for (CIP) antisera to detect the virus in plant phosphate buffer, pH 8.2, with 0.1% 2resistance in peas to BYMV, has been tissues, and notes a new leguminous mercaptoethano . The virus preparation reported to confer resistance to these species, chickpea (Cicer arientinum L.), was centrifuged in 30% (w/v) CsCi

Unusual Intracellular Aggregates of Broad Bean Wilt Virus Particles

SUMMARY A novel aggregation form of particles of a pea isolate of broad bean wilt (BBWV) is described. The aggregates consist of hollow tubules that are square or rectangular in section (quadrangular tubules) and have walls made up of two parallel rows of virions. These aggregates, which may be specific for the virus strain under study, occur in the same tissues as the cylindrical virus tubules typically induced by many other strains of BBWV.