Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. Includes bibliographical references.

Thesis (Ph. D.)--Ludwig-Maximilians-Universität München, 2002. / Title from PDF t.p. (viewed on June 4, 2006). Includes bibliographical references (p. 191-199).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

The effects of detergent action on several photochemical and physical properties of chloroplast lamellae have been investigated. The general observations made by other authors who have employed detergents in previous reports have been largely confirmed. It has not however, been found possible to ascribe any of the particular effects which have been observed on the properties of lamellae, to any characteristic of molecular structure and/or polarity of the detergents studied. One detergent of particular interest has emerged from this survey, in the form of G. 711. No other instance is known of any detergent which is an efficient solubiliser of chloroplast lamellae and yet which does not inhibit System II reactions to a high degree at low concentrations of detergent. Of the two photosynthetic photoacts, least is known of the short wavelength System II. The detergent may be of considerable use in future work on the elucidation of the mechanism of the photosynthetic photoevolution of oxygen from water.

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Introduction: Part 1. Greenhouse studies were conducted to investigate the absorption of sodium, potassium, calcium and magnesium by lemon seedlings. The plants were grown in controlled nutrient solutions and analysis of the plant material was made to determine the relationship between the four cations in the different plant organs. Results of the experiment may be summarized as follows:- The occurrence of leaf burn appeared to be associated with a low calcium content, together with a high sodium, potassium or sodium + potassium content. The development of the seedlings was shown to be markedly influenced by the level of calcium supply and to a much lesser degree by the level of potassium supplied. The concentration of sodium, potassium, calcium and magnesium in the stem and leaf varied with position of the tissues on the main axis. The level of sodium was found to influence the distribution of sodium in the leaves, and the sodium content of the leaf, stem and root tissues gave a good reflection of the level of sodium supplied. The effect of the sodium treatment on the uptake of potassium appeared to be dependent on the calcium content of the tissues. Sodium treatment was found not to affect the leaf calcium content. In the stem and root tissues the calcium content was reduced when the calcium level in the nutrient medium was low, and increased the calcium content of these two tissues at the higher level of calcium supply. The sodium supply was shown to reduce the leaf magnesium only slightly, and its affect on the magnesium content of the stem and root tissues was shown to be dependent on the level of calcium supplied. The potassium content of the leaves, stems and roots increased when the supply of potassium was raised. Increasing the potassium level in the nutrient supply was found to cause a very slight reduction in the sodium content of the leaf, but did not affect the sodium content of the stem and root. Potassium did not affect the calcium content of the leaves and increased the stem calcium when sodium was not present in the nutrient media in high concentrations. In the roots potassium only increase the calcium content at the upper level of calcium supply. The magnesium content of the leaf and stem tissues was reduced as the potassium supply was increased. In the roots the general trend was for the magnesium content to increase when the level of potassium treatment was raised. The calcium content of all the plant parts increased with a rise in the calcium supply, the stem and root tissues having a greater percentage increase than the leaves. The sodium content of the plant tissue was reduced as the level of calcium supply was raised. The leaf potassium content decreased with a higher calcium level of supply. In the stem and roots the potassium content was increased by doubling the calcium supply. The calcium treatment had no influence on the magnesium content of the foliage, but in the stem and root tissues a decrease in magnesium content resulted from an increase in the calcium supply. Part II Potato tuber tissue and carrot root tissue were used as experimental material in the investigation of sodium9 potassium9 and calcium uptake by storage tissue. It was shown that when the tissue disks are transferred from distilled water to a solution of salts there is a rapid initial uptake of cation which is neither particularly selective, nor related to metabolism, but dependent on the external concentration. On the other hand, the prolonged active accumulation of cation exhibits selectivity. Potassium absorption by potato tuber tissue was shown to be stimulated by sodium9 whereas the potassium and calcium absorption by carrot root tissue was shown to be reduced by sodium. Similarly the sodium absorption by the carrot root tissue was reduced by potassium, thus suggesting that the cations compete with one another for the same absorption mechanism.

Proteolytic enzymes are common in plants but are usually specifi to endogenous protein. Plant proteases with specificities applicable to the food industry include papain, ficin and bromelain. Other plants have been used in traditional methods of food preparation for their proteolytic action on food components. The following species were investigated for propagation in tissue culture: Carica papaya, Ficus carica, Cynara cardunculus, Galium verum, Circium arvense, Dieffenbachia amoena, D. picta and Ananas comosus. Tissues of the first five of these demonstrated proteolytic activity by clearing of milk turbidity in agar medium. Commercial papain and ficin preparations are currently obtained from latex of immature papaya and fig fruit, respectively. This investigation was conducted, in part, to determine the feasibility of producing these two enzymes by the in vitro cell culture technique. Standard method of aseptic seed germination and leaf tissue excision were employed for callus initiation. Cell suspension cultures derived from callus were maintained in B5 medium at 28 °C in darkness. Proteolytic activity was determined by a modification of the Food Chemicals Codex method for papain and protein content was determined by Bradford's dye-binding, method. Production of protein and protease varied among cell cultures, but could be influenced by changes to some nutritional factors. Fig cells were grown in medium supplemented with single amino acids in the presence of either nitrate or ammonia as a source of inorganic nitrogen. All nitrate-based media produced higher yields of cell dry weight than ammonia-based media. Glutamic and aspartic acids were most stimulatory growth, protein accumulation and protease activity of fig cells. Skimmed milk, added at 3% (v/v), was a highly effective growth stimulant, and also resulted in higher protein and protease levels than the amino acids. Fresh casein and whey, added individually, produced similar results to skimmed milk. Citric acid, added at the level found in the 3% milk supplement, also caused stimulation of fig cell growth, protein synthesis and protease activity not significantly different from skimmed milk. It appears that nitrogen accumulation and reduction in fig cells may have been limited by an energy requirement which could be satisfied with the addition of citric acid or milk whey to the basal medium. / Land and Food Systems, Faculty of / Graduate

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