<p>Food allergy is an IgE-mediated immunological disease, which affects almost 4% of the adult population and up to 6% of children. Proteins from milk, egg, peanuts, soybean, wheat, fish and nuts are the main cause of food allergies. A less common allergen is pea protein. The National Food Administration analyses undeclared pea protein and contaminations of pea protein in foods using rocket immunoelectrophoresis and immunodiffusion. For both methods an antiserum against pea protein is needed. The aim of this study has been to characterize a newly developed rabbit-antiserum against pea protein. It is important to know if the antiserum is specific against peas, the detection as well as the quantification limits before it can be taken into use. The results of the study show that the antiserum was not absolutely specific, since it cross-reacted with chickpeas, fenugreek and lenses. However there is an "in-house" established PCR-method that can distinguish between chickpeas, fenugreek and peas and that method can be used as a complement to the rocket immunoelectrophoresis. The PCR-method cannot be used alone because it is not quantitative. Rocket immunoelectro¬phoresis detects 0,003% pea protein with purified IgG-antibodies from the antiserum.</p>

A busca por embalagens flexíveis rapidamente degradáveis tem sido intensa nos anos mais recentes. Amidos de variadas fontes têm sido avaliados para a produção de filmes, sendo que a maioria destes apresenta boas características mecânicas e de barreira ao oxigênio, entretanto, uma série de limitações é observada com relação às suas características hidrofílicas e permeabilidade ao vapor d´água. O amido de ervilha normalmente apresenta teores mais elevados de amilose, o que pode melhorar a obtenção da rede formadora de filmes. Além disto, as associações amido-goma podem modificar a gelatinização e retrogradação do amido, processos que interferem na formação de filmes. O acréscimo de plastificantes também tem se mostrado de importância para melhorar as propriedades mecânicas dos filmes. Assim, o objetivo do presente trabalho foi avaliar o efeito da adição de goma xantana e de glicerol ao amido de ervilha verde de alto teor de amilose (cv. Utrillo) na elaboração de filmes e em suas características. Soluções filmogênicas (SF) com diferentes teores de amido de ervilha (3, 4 e 5%), de goma xantana (0, 0,05 e 0,1%) e de glicerol (proporção glicerol-amido de 1:5 p/p) foram estudadas. As SF foram obtidas por ebulição (5 min.), seguida de autoclavagem por 1h. a 120°C. Os filmes foram prepa rados segundo a técnica de casting. O aumento da concentração de amido na solução filmogênica aumentou a espessura, fator de ruptura, resistência à perfuração e solubilidade dos filmes em água. O aumento da concentração da goma xantana interferiu apenas nas propriedades associadas à cor dos filmes, aumentando os valores da tonalidade e decrescendo o croma a* e a transparência. O aumento da concentração do glicerol interferiu nas propriedades mecânicas dos filmes, gerando redução dos valores de resistência máxima à tração, tensão na ruptura, resistência à perfuração e fator de ruptura. O plastificante também gerou aumento do alongamento na ruptura, redução da transparência e aumento da espessura e da solubilidade do filme em água. / In the past few years, the attempt to obtain degradable flexible packaging has increased considerably. In this sense, starches obtained from different botanical sources have been evaluated to produce films. Most of these films present good mechanical characteristics and provide a good barrier to oxygen. Nevertheless, some limitations have been observed in relation to their hydrophilic properties and permeability to water vapor. Studies using starch from green peas with high levels of amylose to produce films were not found in the literature. The higher levels of amylose can improve the achievement of the matrix that forms films. In addition, starch-gum associations can modify starch gelatinization and retrogradation, processes which interfere with film formation. The addition of plasticizers has also been considered important to improve the mechanical properties of films. The aim of this study was to evaluate the effect of the addition of xanthan gum and glycerol to the starch of green peas with high content of amylose (cv. Utrillo) in the preparation of films and in their features. Filmogenic solution (FS) with different levels of pea starch (3, 4 and 5%), xanthan gum (0, 0.05 and 0.1%) and glycerol (glycerol-starch ratio of 1:5 p/p) were tested. The FS was obtained by boiling (5 min.), followed by autoclaving for 1h. at 120°C. The films were prepared by casting. The increased concentration of starch in the solution increased the thickness, factor of rupture, puncture force and solubility of films in water. Increasing amounts of xanthan affected only the properties associated with the color of the films, increasing the values of hue angle and decreasing the chroma a* and transparency. The increased concentration of glycerol interfered in the mechanical properties of the films, causing reduction of the maximum values of tensile strength, strain at break, puncture force and factor of rupture. The plasticizer also caused an increase of elongation at break, reduced transparency and increased thickness of the film and the solubility in water.

<p>This investigation addresses how photosynthetic efficiency is affected when pea (Pisum sativum) plants are restricted to a sole nitrogen source (i.e. ammonium or nitrate). The pea plants were watered with different nutrient solutions without NO3- or NH4+ for different time-periods in order to assay for nitrogen content. The soluble ammonium and nitrate content was measured throughout the entire growth period. No major differences were observed in nitrogen content during the starvation period up to 25 days. For technical reasons, cultivation of plants could not be extended beyond this time. The chloroplasts and thylakoids were isolated after 25 days and assayed for chlorophyll contents and photosynthetic activity.</p><p>The outcome of these tests indicates a small but unambiguous decrease in the photosynthesis activity for all treatments, relative the control.</p>

This investigation addresses how photosynthetic efficiency is affected when pea (Pisum sativum) plants are restricted to a sole nitrogen source (i.e. ammonium or nitrate). The pea plants were watered with different nutrient solutions without NO3- or NH4+ for different time-periods in order to assay for nitrogen content. The soluble ammonium and nitrate content was measured throughout the entire growth period. No major differences were observed in nitrogen content during the starvation period up to 25 days. For technical reasons, cultivation of plants could not be extended beyond this time. The chloroplasts and thylakoids were isolated after 25 days and assayed for chlorophyll contents and photosynthetic activity. The outcome of these tests indicates a small but unambiguous decrease in the photosynthesis activity for all treatments, relative the control.

Food allergy is an IgE-mediated immunological disease, which affects almost 4% of the adult population and up to 6% of children. Proteins from milk, egg, peanuts, soybean, wheat, fish and nuts are the main cause of food allergies. A less common allergen is pea protein. The National Food Administration analyses undeclared pea protein and contaminations of pea protein in foods using rocket immunoelectrophoresis and immunodiffusion. For both methods an antiserum against pea protein is needed. The aim of this study has been to characterize a newly developed rabbit-antiserum against pea protein. It is important to know if the antiserum is specific against peas, the detection as well as the quantification limits before it can be taken into use. The results of the study show that the antiserum was not absolutely specific, since it cross-reacted with chickpeas, fenugreek and lenses. However there is an "in-house" established PCR-method that can distinguish between chickpeas, fenugreek and peas and that method can be used as a complement to the rocket immunoelectrophoresis. The PCR-method cannot be used alone because it is not quantitative. Rocket immunoelectro¬phoresis detects 0,003% pea protein with purified IgG-antibodies from the antiserum.

Soilborne plant pathogens are responsible for many of the major crop diseases worldwide. However, plant root tips are generally resistant to pathogen infections. The goal of this dissertation research is to understand the mechanism of this natural resistance by testing the hypothesis that root caps and root border cells control the rhizosphere community through the biological products which they deliver to the soil. Specific objectives of this dissertation project are 1) identifying, isolating, and characterizing the genes important for border cell development and for root exudates delivery, and 2) analyzing the function of extracellular macromolecules in root exudates in root tip-fungal pathogen interaction. The expression of a primary cell wall synthesis gene, PsFut1, encoding Pisum sativum fucosyltransferase, was characterized during border cell production, and the impact of silencing this gene on border cell development was examined. Another gene, BRDgal1, encoding β-galactosidase, was identified and characterized in Pisum sativum during this study. It was shown that this β-galactosidase is specifically produced in and secreted from root border cells. The microarray transcriptional profiling in M. truncatula and mRNA differential display analysis in pea plants were carried out following the induction of border cell production to gain a broader understanding of the genes which potentially influence border cell development. In order to study the commonality of border cell production across different plant species, the expression of rcpme1, the marker gene for border cell production, was compared between the garden pea and a gymnosperm species, the Norway spruce (Picea abies). To accomplish the second objective, the focus of this study was shifted from border cell development to mucilaginous root exudates excreted by border cells and root cap cells. This resulted in a breakthrough in the understanding of the mechanisms of root tip resistance. The presence of extracellular DNA in the root mucilage was discovered and its requirement for root tip resistance to fungal infection was demonstrated. Extracellular proteins in the root mucilage were identified and they were shown to be also required for the root tip resistance to fungal infection. This work provided new insights into understanding plant defense mechanisms.

The pea weevil (Bruchus pisorum L.) is the most significant pest of field pea (Pisum sativum L.) in Australia. The only available means for controlling pea weevil at the present time is with chemical pesticides. The aim of this study was to introgress natural pea weevil resistance, derived from the wild pea species, Pisum fulvum Sibth. & Sm. into cultivated field pea and devise strategies for screening for the resistance with breeding applications. Traditional breeding methods were used to transfer pea weevil resistance from P. fulvum accession ‘ATC113’ to cultivated field pea, cv. ‘Pennant’. Progeny derived from this population were examined for inheritance of pod and seed resistance. Seed resistance in F2 plants segregated in a ratio of 1:37:26 (resistant: mixed response: susceptible), indicating a trigenic mode of inheritance (1:63), with at least three major recessive genes controlling pea weevil resistance. Seed resistance was conserved over consecutive generations (F2 to F5) and was successfully transferred to populations crossed with a second adapted field pea variety‘Helena’. Pod resistance presented as a quantitative trait in the F2 population, but this resistance was not retained in subsequent generations. Amplified fragment length polymorphisms (AFLPs) were sought in the parents and in resistant and susceptible F3 plants. Restricted maximum likelihood (REML) analysis was used to identify 13 AFLP markers with a statistically significant association with pea weevil resistance and 23 with pea weevil susceptibility. Principal coordinate analysis (PCO) showed that the AFLP marker loci formed clusters in the PCO space, which could indicate the three proposed gene locations. Eight AFLP markers were cloned, sequenced and converted to sequence characterised amplified regions (SCAR). Two SCAR markers, SC47359 and SC47435 were polymorphic between the resistant and susceptible parents. Both markers co-segregated with the resistant lines and with 30-36% of susceptible lines. Plants which did not possess either band were highly susceptible. The other PCR products were either monomorphic between the resistant and susceptible parents or produced more than one band product. A range of phenotypic traits was measured in the F2 population derived from the hybridisation between P. fulvum and P. sativum and associations with pea weevil resistance were made. In the F2 population, pea weevil resistance was not correlated with any of the negative traits originating from the wild parent, such as increased basal branching, dark seed coat or small seed size, neither was resistance correlated with flower colour, flowering time or seeds per pod. Pea weevil resistance should therefore be transferable with minimal linkage drag. A convenient morphological marker, such as flower or seed colour was not identified in this study based on these results. Using principal component analysis (PCA) as a visual tool, resistant and semi-resistant plants in the F3 and ‘backcross’ introgression populations were identified with improved trait performance compared with the wild parent

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 4 uppsatser.

The diploma thesis deals with the determination of mobile forms of mercury using the technology of diffusion gradient in thin-film. The theoretical part deals with the occurrence of chemical forms of mercury in the environment, mercury effects on plants and methods of determination of mercury's mobile forms. In the practical part, the accumulation of mercury from soils into various organs of garden pea (Pisum sativum L.) was observed. Soil samples were taken in Brno, in streets Opuštěná and Zvonařka. The contents of mercury in soils ranged from 0,32618 +- 0,02493 mg.kg-1 to 0,08382 +- 0,00255 mg.kg-1. Only 0,15 - 0,20 % of the mercury passed from the soil into the soil solution. Only 2,21 to 3,45 % of mercury was available for the soil solution for DGT units and therefore also for the plants. The mercury content in the soil influenced the amount of mercury in the garden pea. The highest concentrations of mercury were detected in the leaves and roots, the lowest concentrations were in the consumed parts of garden pea. The significant correlations were found out between the content of mercury's mobile forms provided by DGT method and the mercury content in roots, leaves and stem of garden pea (correlation coefficients from 0,913 to 0,984). Simulation of acid rains did not demonstrate the raise of mercury's mobility relating to the increase of the acidification of the soil.

No description available.