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[Typewritten] Includes bibliography.

Bibliography: leaves 200-223. / xii, 225, [15] leaves, [19] leaves of plates : ill. (some col.), maps (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1995?

Bibliography: leaves 200-223.

In order to elucidate the component(s) of yellow peas responsible for their health benefits, the effects of 10 or 20 g of isolated yellow pea protein (P10 and P20) or fibre (F10 and F20) on food intake (FI) at an ad libitum pizza meal served at 30 min (experiment 1) or 120 min (experiment 2), blood glucose (BG) and appetite in young healthy males (20-30 y) were investigated. In experiment 1, P20 suppressed FI compared to all other treatments and lowered cumulative FI (pizza meal kcal + treatment kcal) compared to F10. Protein treatments suppressed pre-meal (0-30 min) BG compared to control, whereas only P20 suppressed post-meal (50-120 min) BG. In experiment 2, there was no effect of treatment on any outcome measures. Thus, protein is the component responsible for the short-term effects of yellow peas on glycaemia and FI, but its second-meal effects diminish by 2 hours post-consumption.

In order to elucidate the component(s) of yellow peas responsible for their health benefits, the effects of 10 or 20 g of isolated yellow pea protein (P10 and P20) or fibre (F10 and F20) on food intake (FI) at an ad libitum pizza meal served at 30 min (experiment 1) or 120 min (experiment 2), blood glucose (BG) and appetite in young healthy males (20-30 y) were investigated. In experiment 1, P20 suppressed FI compared to all other treatments and lowered cumulative FI (pizza meal kcal + treatment kcal) compared to F10. Protein treatments suppressed pre-meal (0-30 min) BG compared to control, whereas only P20 suppressed post-meal (50-120 min) BG. In experiment 2, there was no effect of treatment on any outcome measures. Thus, protein is the component responsible for the short-term effects of yellow peas on glycaemia and FI, but its second-meal effects diminish by 2 hours post-consumption.

Germinating pea (Pisum sativum L.) roots were divided into five sequential 0.5 cm segments from the root tip. Pooled segments were analyzed for their protein, starch and lipid content as an indirect indication of plastid function. Fresh weights of root segments were lowest in the tips (4.45mug per segment) and progressively higher up to the fifth segment (11.09mug per segment). Total protein, starch and lipid content, on a per segment basis, were all highest in zone 1 (tip segment) and progressively lower up to zone 5. Plastids were isolated from each of the five root segments and analyzed for their capacity for lipid biosynthesis under several different in vitro conditions. Collectively, the observations presented here suggest that the relative contributions of plastids to the overall physiology of germinating pea roots gradually diminishes as root development proceeds, and that plastids isolated from progressively older root zones have increased capacity for glycolytic and/or pentose phosphate metabolism. (Abstract shortened by UMI.)

Risk assessment of trace-metal contamination in soils requires predictive models that can accurately describe the complex uptake processes at the soil-plant interface, which are usually characterized by the coexistence of and interaction between multiple components. Competing cations such as Ca and H can affect metal availability to plants and subsequent rhizotoxicity. The biotic ligand model (BLM) has been proposed as a promising approach to model these interactive processes. Under the BLM assumption, we designed experiments to investigate how the solution chemistry is correlated with metal uptake and rhizotoxicity. Our first goal is to acquire a set of BLM parameters that can accurately represent the experimental data over varied solution conditions and parameters that are easy to integrate with general speciation models. The second objective is to get insight into the physical nature of the interactions. Our titration experiments revealed three types of biotic ligands in the pea roots with defined site densities and stability constants with H. Our ion sorption experiments estimated the surface-adsorption stability constants of Ca, Mg, Cd, Cu, Ni, and Zn with excised fresh pea roots. Our 48-h root growth tests have established the formation constants (KMe's) of living pea roots with Ca, Cd, Cu, Ni, and Zn. In these studies, we hypothesized and confirmed that the concentration of the metal-root complexes correlated with observed rhizotoxicity and that Ca, H, and trace metals competed for root absorption where lower solution pH decreased both Ca and metal uptake. Root elongation was found to be highly sensitive to root Ca content rather than merely to the direct toxic effects of the trace metals. It is shown that the physiological complexity arising from a living root affected our modeling so that adjustable KMe values, as a function of solution and root chemistry, are required for good model fits. The established model parameters were tested in hydroponic mixture solutions for their ability to predict the uptake of multiple metals simultaneously. The joint effects of Cd, Cu, and Ni in mixtures on root growth were studied and the potential interactions between these ions were also investigated.

The interaction between the glycolytic metabolism and fatty acid and glycerolipid biosynthesis in pea root (Pisum sativum L.) plastids was assessed in this study. When various glycolytic intermediates were used to substitute for the APT requirement for fatty acid synthesis from acetate, phosphoenolpyruvate, 2-phosphoglycerate, fructose-6-phosphate and glucose-6-phosphate each gave 48, 17, 23 and 17%, respectively, of the ATP-control activity. Similarly, in the absence of exogenously supplied ATP, the optimized triose-phosphate shuttle, which consists of 2 mM dihydroxyacetone phosphate, 2 mM oxaloacetic acid and 4 mM inorganic phosphate, gave up to 44% the ATP-control activity in promoting fatty acid synthesis from acetate. These results suggest that 3-phosphoglycerate kinase and pyruvate kinase in these plastids can function in intraplastidic ATP production through substrate level phosphorylation. However, in all cases, exogenously supplied ATP gave the greatest rates of fatty acid and glycerolipid synthesis. Radiolabeled pyruvate, glucose, glucose-6-phosphate, and malate in comparison to acetate were all variously utilized for fatty acid and glycerolipid biosynthesis by the root plastid. At the highest concentrations tested (3-5 mM), the rates of incorporation of pyruvate, glucose-6-phosphate and acetate into fatty acids were 183, 154, 125 nd 99 nmol $ rm cdot h sp{-1} cdot mg sp{-1}$, respectively. Malate was the least effective precursor, giving less than 55 nmol $ rm cdot h sp{-1} cdot mg sp{-1}$. Acetate incorporation was approximately 55% dependent on exogenously supplied reduced nuclotides (NADPH and NADH), whereas the utilization of the remaining precursors was only approximately 10-20% dependent on NAD(P)H. These results indicate that the entire pathway of carbon flow from glycolysis, including pyruvate dehydrogenase (PDHase), to fatty acids is operating in pea root plastids. Further, the intraplastidic glycolytic pathway plays an important role in provi

The effect of utilization of pulse flours with coarse and fine particle size milled from green lentils, yellow peas, navy beans, and pinto beans in pita bread and pan bread was studied. Composites containing 25, 50, 75, and 100% pulse flours were studied for pita baking, and 10, 15, and 25% for pan bread baking. Addition of the pulse flours produced pitas with the pockets, but they were smaller in diameter and firmer in texture than the wheat control. Supplemented pan bread had lower specific loaf volume and firmer crumb with coarser grain. The recommended tolerance levels of pulse flour addition were 25% for pita bread and 10-15% for pan bread depending on the pulse flour and particle size. It appears that navy beans and pinto beans are more suitable for baking applications using composite flours than lentils and yellow peas, and coarse flours produced breads with improved quality compared to fine flours.