Bioavailability and Rhizotoxicity of Cd to Pea (Pisum sativum L.)

Risk assessment of cadmium (Cd) contamination in soils requires identifying the bioavailable portion of the total Cd, a portion that is determined by environmental conditions such as pH and calcium (Ca) level in soils and by the physiological processes going on in the plant roots. Growth tests in solutions were conducted to develop a terrestrial biotic ligand model to describe uptake and rhizotoxicity of Cd to pea (Pisum sativum L. cv. Lincoln). Inhibition concentration associated with a 50% reduction in root elongation (IC₅₀) values were found to vary with external Ca²⁺ and H⁺ activities. Root-bound Ca was found to reach a plateau of about 63 µmol g^?1 (dry weight) although Ca treatment increased from 0.04 to 2 mmol L^?1. When experimental treatments (e.g., pH 6, Ca 0.2 to 2 mM) resulted in sufficient Ca supply, dose–response curves relating root elongation to root-bound Cd could be modeled with Weibull equations; IC₅₀ values were expressed in terms of root-bound Cd concentration. When the treatments (e.g., pH 4 or 5, Ca 0.04 mM) suggested a low Ca supply, root elongation was more sensitive to Ca content and root-bound Ca concentration became the dominant predictor variable. Cd accumulation was modeled by treating the pea roots as an assemblage of biotic ligands with known site densities (Q _Lj ) and proton binding constants (K _HLj ). The logK _Ca and logK _Cd values were established using measured root-bound ion concentrations and solution chemistry. The logK _Ca values were negatively correlated to root Ca contents. The logK _Cd values were positively correlated to logK _Ca values. Explanations for the changing of constants are discussed.     

Identification and Characterization of Slow Rusting Components in Pea (Pisum sativum L.)

Three hundred and forty five accessions of pea of diverse origin, height, leaf types and disease reaction were screened for rust disease severity and area under disease progress curve (AUDPC). The frequency of slow rusting types in the tall, dwarf, early and late groups appeared comparable. Of the 345 accessions, forty-four genotypes were evaluated for disease intensity, which was converted into AUDPC, number of pustules/leaf and pustule size. Wide range of variation was found for these traits. The slow rusting attribute of 16 genotypes was further confirmed by testing these under unprotected (inoculated) and protected (fungicidal spray) conditions for two successive years for disease intensity by assessing the AUDPC, seed yield/plot, and 100-seed weight. The fast rusting genotypes exhibited lower AUDPC, accompanied with increased seed yield and seed weight when grown under the protected condition, as compared to those raised under the unprotected condition. The genotypes Pant P 11, FC 1, HUDP 16, JPBB 3 and HUP 14 appeared as slow rusting genotypes.     

Modelling nitrogen fixation of pea ( Pisum sativum L.)

Abstract

Nitrogen fixation was simulated for a leafless variety (Delta) of pea (Pisum sativum L.) in central Sweden. It is assumed that N₂ fixation is basically proportional to root biomass, but limited by high root N or low substrate carbon concentrations. Input data on root carbon and nitrogen were estimated from observations of above-ground biomass and nitrogen. The simulated N₂ fixation was compared with estimated values from observations using the ¹⁵N labelling technique. Test data were taken from pea monocultures and pea-oat mixtures with varying pea biomass levels during 1999. Simulated within-season accumulated N₂ fixation correlated to the estimated N₂ fixation with a correlation coefficient (R ²) of 0.74. For seasonal simulations, the predictability was higher (R ²=0.93). Two alternative non-dynamic models, estimating seasonal N₂ fixation as proportional to above-ground biomass and above-ground N, respectively, gave lower predictability (R ²=0.83 and 0.80, respectively). The models were also applied to a second year (1998) and two other sites by comparison with accumulated N₂ fixation estimated by the Difference method. A halved specific N₂ fixation rate (expressed per unit of root biomass) in 1999, compared with 1998, corresponded to essentially dryer and warmer soil conditions during 1999. It was indicated that the variations in soil moisture were more important than soil temperature. It was concluded that the abiotic responses might be of great importance for modelling N₂ fixation rate under different soil conditions.     

Nutritional assessment in vitro and in vivo of raw and extruded peas (Pisum sativum L.)

The effects of extrusion cooking on the nutritional properties of Pisum sativum L. have been evaluated in vitro and in vivo. The treatment greatly elevated protein and starch digestibility in vitro. Also, the amounts of intact starch diminished while total free sugars increased. In addition, the levels of antinutritional factors, such as protease inhibitors and lectins, were greatly decreased. Concentrations of methionine and cystine were low in raw peas and were further reduced by extrusion treatment. The nutritional performance of rats fed extruded pea diets for 15 days was no better than that of rats given raw pea diet. This was due to the overriding effects of amino acid deficiencies in the diets. Weight gains by rats fed extruded pea diets supplemented with amino acids were, however, much higher than those achieved by rats fed supplemented raw pea diets. Food transformation index and protein efficiency ratio values were also greatly improved. Extrusion treatment did therefore significantly improve the nutritional quality of peas.     

Nitrate alters the flavonoid profile and nodulation in pea (Pisum sativum L.)

A rhizosphere application of NO _inf3 ^sup- and/or naringenin affected the Pisum sativum — Rhizobium leguminosarum biovar viciae symbiosis. NO _inf3 ^sup- (5 mM) lowered while naringenin raised the nodulation status (nodule numbers and weight) and nodule efficiency (C₂H₂ reduction activity). However, the inhibitory effect of NO _inf3 ^sup- was to some extent alleviated when applied in combination with naringenin. The plant biomass was increased by the application of NO _inf3 ^sup- and naringenin, either alone or in combination, while a higher root: shoot ratio was observed only in the naringenin-treated plants. Root flavonoids are known to regulate the expression of nod genes; their high-performance liquid chromatography profile was influenced in different ways by NO _inf3 ^sup- and naringenin.     

Effects of Brussels sprout juice on the cell cycle and adhesion of human colorectal carcinoma cells (HT29) in vitro

Consumption of Brassica vegetables is associated with a reduced risk of cancer of the alimentary tract in animal models and human populations. We used raw juice extracted from Brussels sprouts rich in the glucosinolate sinigrin to explore the effect of naturally occurring glucosinolate breakdown products on cell cycle progression and apoptosis in human colorectal carcinoma cells (HT29). Juice was prepared from sprout tissue immediately before use, and the glucosinolate breakdown products were determined by gas chromatography mass spectrometry and liquid chromatography mass spectrometry. The cell cycle was analyzed by flow cytometry on detached and adherent cells, and apoptosis was measured in the detached population by annexin V staining. Twenty-four hours after challenge with juice (10 microL/mL), 7-13% of adherent cells had detached from the substratum but the majority (82%) of these cells had not entered apoptosis, whereas only 33% of detached control cells were not apoptotic (p < 0.05). The main glucosinolate breakdown products were as follows: the sinigrin breakdown product, 1-cyano-2,3-epithiopropane (ca. 38 mM); the gluconapin hydrolysis product, 3-butenyl isothiocyanate (ca. 2.2.mM); the glucobrassicin metabolite, ascorbigen (ca. 8 mM); and low concentrations of other indole glucosinolate-derived hydrolysis products such as neoascorbigen and 3,3'-diindolylmethane. A variety of biologically active glucosinolate breakdown products are released by mechanical disruption of raw Brussels sprout tissue, but contrary to previous assumptions, allyl isothiocyanate is not the main compound responsible for the inhibition of cell proliferation.     

Yield structure components of autumn- and spring-sown pea (Pisum sativum L.)

ABSTRACT

Climate change brings increasing attention to winter sowing of traditionally spring sown crops. Crop stand height, soil coverage, grain yield and yield components of six winter pea varieties and one spring pea variety were compared in eastern Austrian growing conditions in 2014 and 2015. Crop stands of winter pea were taller up to the end of May before they declined and crop stands of spring pea were taller from early June on. Winter pea covered the soil at least partly over winter and showed faster soil coverage in spring. At the end of May, just some weeks before harvest, spring pea attained equal soil coverage. Grain yield of winter pea was almost double that of spring pea due to higher pod density whereas spring pea produced more grains pod^?1 than four out of six winter pea varieties and a higher thousand grain weight than all winter pea varieties. Consequently, grain density was higher for winter pea while the single pod yield was higher for spring pea. Growing winter peas in Central Europe might be a good strategy for increasing grain legume productivity and thereby European feed protein production.     

Carbon costs of nitrate reduction in broad bean (Vicia faba L.) and pea (Pisum sativum L.) plants

The present study aimed at the assessment of carbon (C) costs for nitrate reduction by measuring the additional CO₂ amounts released from roots of nitrate‐fed plants in comparison with urea‐fed plants. Only roots were suitable for these determinations, because nitrate reduction in illuminated shoots is fed nearly exclusively by reducing equivalents coming directly from photosynthetic processes. Therefore, in a first experiment, the sites of nitrate reduction were determined in nodule‐free broad bean (Vicia faba L.) and pea (Pisum sativum L.) plants grown in pots filled with quartz sand and supplied with KNO₃. The extent of nitrate reduction in the various plant organs was determined by measuring in vitro nitrate reductase activity and in situ ¹⁵NO reduction. Only between 9% and 16% of nitrate were reduced in roots of German pea cultivars, whilst 52% to 65% were reduced in broad bean roots. Therefore, C costs of the process could be determined only in broad bean, using an additional pot experiment. The C costs amounted to about 4.76 mol C (mol N)^–1 or 4 mg C (mg N)^–1, similar to those measured earlier for N₂ fixation. The high proportion of nitrate reduction in shoots of pea plants implies that only very little C is required for this nitrate fraction. This can explain the better root growth of nitrate‐nourished pea plants in comparison with N₂‐fixing organisms, which need C compounds for N₂ reduction in roots. Moreover, a different availability of photosynthates in roots of plant genotypes could explain physiologically the occurrence of “shoot and root reducers” in nature.     

Change in particle size of pectin reacted with pectinesterase isozymes from pea (Pisum sativum L.) sprout

Four pectinesterase (PE) isozymes were isolated by CM-Sepharose CL-6B chromatography from etiolated pea (Pisum sativum L.) sprouts and then reacted with citrus pectin (degree of esterification = 68%, 30-100 kDa) to observe the change in pectin particle size using a laser particle size analyzer. After incubation of a pectin-PE mixture (pH 6.5) at 30 degrees C for 4 h, PE 1 was observed to catalyze the transacylation reaction most remarkably, increasing the particle size from approximately 50-70 to approximately 250-350 nm, followed by PE 3, PE 2, and PE 4.     

Influence of soil humic substances and herbicides on the growth of pea (Pisum sativum L.) in nutrient solution 1

No morphological and length modifications of the root and shoot systems are apparent in pea (Pisum sativum L.) plants of three varieties grown in the presence of 100 mg/L humic acid or fulvic acid or 20 mg/L linuron [3‐(3,4‐dichlorophenyl)‐l‐methoxy‐l‐methylurea] or ametryne [2‐ethylamino‐4‐iso‐propylamino‐6‐methylthio‐1,3,5‐triazine]. A combination of humic substance and herbicide at these concentrations produces in all pea varieties a differentiated and marked reduction in root length and large morphological alterations of roots. Statistical analysis of data show that differentiated and highly significant or significant effects are produced on the shoot and root dry weight by either the humic substance or herbicide alone, and by any combination of two or three factors considered (variety, humic substance, herbicide).     

Influence of maturation on the alteration of allergenicity of green pea (Pisum sativum L.)

The IgE-binding capacity of different maturation levels of green pea seeds (Pisum sativum L.) of the variety Maxigolt is examined to determine the influence of maturation on the alteration of allergenicity. Different protein extraction methods to get total protein extracts and the protein fractions glutelin, globulin, and albumin from different maturation levels of green pea seeds are applied to SDS-PAGE/silver staining as well as SDS-PAGE/immunoblotting and EAST inhibition experiments using sera of 15 green pea allergic individuals. The SDS-PAGE/silver-staining experiments show the continuous change of protein pattern during maturation. SDS-PAGE/immunoblot and EAST inhibition demonstrate that all levels of green pea seeds show relevant IgE-binding capacity, as do immature seeds. Total IgE-binding capacity rises with the progress of maturation. Although the main allergenic activity is dependent upon the albumin fraction, the glutelin and globulin fractions are also important. The implication of these results is an obvious allergenic potency of all maturation levels, even immature seeds, whereas an increase of allergenicity during maturation could be notched up. The highest allergenic potency is caused by the albumin fraction, but globulin and glutelin fractions also contribute to the allergenicity of green pea.     

Effect of germination on the carbohydrate composition of the dietary fiber of peas (Pisum sativum L.)

The effect of different conditions of pea germination on dietary fiber (DF) composition was studied. Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) were subjected to acid hydrolysis, and the resultant neutral sugars, uronic acids, and Klason lignin were quantified. Germinated peas exhibited significantly higher contents of total dietary fiber (TDF) than the raw sample, due to the increases of both DF fractions. Under darkness conditions, germination exhibited the highest contents of IDF and SDF. Decreasing IDF/SDF ratios showed that the carbohydrate changes did not take place to the same extent during germination, the SDF fraction being the most affected. The detailed chemical composition of fiber fractions reveals increases of cellulose in the IDF of germinated samples, whereas SDF exhibits a decrease of pectic polysaccharides and also increases of polysaccharides rich in glucose and mannose. The DF results were corroborated by a comparative examination of the cell wall carbohydrate composition.     

HPLC determination of chlorophyll and carotenoid pigments in processed green pea cultivars (Pisum sativum L.)

Chlorophyll and carotenoid pigments from six cultivars of processed green peas (Avola, Tristar, Rampart, Turon, Bella, and Greenshaft) were extracted with 100% acetone and analyzed by reversed-phase HPLC. A total of 17 pigments were identified in the pea cultivars including 8 xanthophylls ((all-E)-neoxanthin, (9'Z)-neoxanthin, (all-E)-violaxanthin, neochrome, (all-E)-lutein epoxide, (all-E)-lutein, neolutein B, neolutein A), 4 chlorophyll b related compounds (chlorophyll b derivative, chlorophyll b, chlorophyll b', and pheophytin b), 4 chlorophyll a related compounds (chlorophyll a derivative, chlorophyll a, chlorophyll a', and pheophytin a), and (all-E)-beta-carotene. The efficiency of different extraction procedures using 100% acetone showed that initial extraction followed by three reextractions without holding time between gave a higher extraction yield than no reextraction and 30 or 60 min holding time. All six cultivars contained the same pigments, but the concentration of each pigment varied significantly. On average of the two years, the chlorophyll a concentration varied from 4800 to 7300 microg/100 g fresh weight, the chlorophyll b concentration from 2100 to 2800 microg/100 g fresh weight, the (all-E)-lutein concentration from 1200 to 1900 microg/100 g fresh weight, and the (all-E)-beta-carotene concentration from 300 to 490 microg/100 g fresh weight in the processed pea cultivars. These differences in pigment concentration between the investigated cultivars are discussed in relation to maturity, product color and nutritional quality.     

Evaluation of Dry Peas (Pisum sativum L.) Varieties for Seedling Vigor Indices in Eastern Montana

Genetic and environmental factors lead to a variation in yield and protein content of dry pea (Pisum sativum L.) seeds. The quality of seed, particularly seed vigor, also influences the establishment of crop and thus final grain yield. The area and production for dry peas are increasing in the Northern Great Plains but knowledge is lacking on how the pea lines/varieties differ in the seed vigor at seven leaf stage. This field and greenhouse study evaluated the eight dry pea lines/varieties for seedling vigor indices and correlated them with grain yield and protein concentrations. Significant differences were observed among the lines/varieties for nodule number plant^?1 in greenhouse, and grain yield in field conditions. The highest number of nodules plant^?1 was obtained with the line MT632, which were at par with lines MT457, and MT190. The highest Vigor Index I was achieved with line MT632 associated with their more shoot lengths as compared to other lines/varieties. The highest Vigor Index II was obtained by variety Majoret and line MT632. The variety DS Admiral yielded 5205 kg ha^?1, which was 17.4 and 33.3% higher than lines MT460 and MT190, respectively. The highest seed protein content was obtained with variety Majoret (23.4%) having highest Vigor Index II and seed yield (4940 kg ha^?1) at par with variety DS Admiral. The lowest seed protein was found with variety DS Admiral (20.3%). The line named MT190 showed lowest yield potential along with the lower protein contents also. Studies show a positive and significant correlation between biomass and Vigor Index I only. Plant nitrogen uptake was positively and significantly correlated with biomass and Vigor Index I in greenhouse only. The results also indicated that seed vigor indices did not reveal any significant correlations with dry peas yield and protein content, so more efforts are needed to evaluate varieties for higher yield and protein content during initial stages of growth in order to maximize their acreage and productivity.     

The Effect of Arbuscular Mycorrhizal Fungi Inoculation in Mitigating Salt Stress of Pea (Pisum Sativum L.)

ABSTRACT

Salinity is one of the major threats to an agriculture production system and limits crop growth and productivity. Arbuscular mycorrhizal fungi (AMF) form a mutualistic association with majority of land plants and play important role in stress tolerance. In the present study, effect of three mycorrhizal treatments, i.e., single-species AMF (Rhizoglomus intraradices), formulated AMF (Funneliformis mosseae and R. intraradices), and multispecies AMF (Rhizoglomus fasciculatum and Gigaspora sp.) along with control (nonmycorrhizal) on growth, yield performance, and metabolic changes in pea crop under salinity stress was examined in completely randomized design with four replications. The results revealed that AMF inoculation mitigated negative effects of salinity in pea due to higher nutrient uptake, accumulation of compatible osmolytes, and lower cellular leakage of electrolyte which in turn enhanced biomass production, chlorophyll synthesis, yield, and growth attributes. Overall, consortium-based application of R. fasciculatum and Gigaspora sp. was found most suitable approach to ameliorate the salt stress in pea crop and enhanced the yield by ~11%, 24%, and 54% than single-species, multispecies, and control treatments, respectively. The variation in results under different mycorrhizal treatment might be due to specific compatibility relationships that exist between symbionts.     

Influence of Dual Inoculation of AM Fungi and Rhizobium on Growth Indices,Production Economics,and Nutrient Use Efficiencies in Garden Pea (Pisum sativum L.)

Field experimentation was conducted at Palampur, India during 2011–2012 in an acid Alfisol to quantify the influence of integrated use of arbuscular mycorrhizal fungi (AMF), Rhizobium and inorganic nitrogen (N) and phosphorus (P) on growth, productivity, profitability, and nutrient use efficiencies in garden pea (Pisum sativum L.). The experiment was laid out in randomized block design (RBD) replicated thrice comprising 13 treatments involving AMF (Glomus mosseae), Rhizobium (R. leguminosarum), and inorganic N and P fertilizers. The results revealed that dual inoculation of pea seed with AMF and Rhizobium enhanced the plant height, leaf area index, and dry matter accumulation significantly by 19.4 and 13.1, 10.7 and 10.7, and 16.6 and 16.7%, respectively at 60 and 120 days after sowing (DAS). Similarly, dual inoculation exhibited significant respective increases of 9.5 and 14.6% in absolute and crop growth rates over generalized recommended NP potassium (K) dose (GRD) during 60–120 DAS. The dual inoculation led to significant respective increases of 1.0 and 2.2, 1.06 and 1.74, 0.21 and 1.5, and 1.05 and 1.60 folds in partial factor productivity, crop recovery efficiency, physiological efficiency, and % recovery of applied N and P, respectively over GRD. The magnitude of increase in pea productivity, net returns, and boron to carbon (B:C) ratio following dual inoculation was to the tune of 20, 54.4, and 104.1%, respectively over GRD. Dual inoculation also exhibited significant increases of 19.4 and 53.1% in production and monetary efficiencies of pea over GRD. Overall, dual inoculation of AMF and Rhizobium with 75% soil-test-based N and P dose in pea has great potential in enhancing pea productivity, profitability, and nutrient use efficiency besides saving about 25% fertilizer N and P without impairing pea productivity in Himalayan acid Alfisol.     

Effects of grinding and thermal treatments on hydrolysis susceptibility of pea proteins (Pisum sativum L.)

The effects of three particle sizes with two types of grindings and two thermal treatments on pea protein extraction (PE) and susceptibility to in vitro enzymatic hydrolysis (pepsin plus trypsin) were studied. Degrees of hydrolysis (DH) were calculated. Remaining peptides were detected by SDS-PAGE and identified by immunoblotting and MS/MS spectrometry. The increase in particle size decreased PE and DH due to a restricted access of solvents and enzymes to proteins. The thermal treatment induced a decrease in PE but did not modify DH. Heating improved legumin (alphaM) and convicilin pepsin hydrolyses but reduced the pea albumin 2 (PA2) hydrolysis. After pepsin and trypsin hydrolysis, only peptides from vicilin and lectin were identified by LC-MS/MS analyses, whatever the treatment.     

Identification and revealing the potential traits of the unique germplasm with extended funiculus in pea (Pisum sativum L.)

Genetic Resources and Crop Evolution - An atypical morphotype of pea (Pisum sativum L.) was identified during the germplasm characterization programme at the Indian Council of Agricultural...