Thesis (Ph. D.)--University of Idaho, 2005. / Also available in PDF format. Abstract. "December 2005." Includes bibliographical references.

The overall objective of these experiments was to augment our understanding of how naphthenic acids stimulate metabolism and growth of bean plants. Three separate studies were carried out with bush bean plants (Phaseolus vulgaris L. cultivar Top Crop) to determine: 1) the effect of potassium naphthenates (KNap) on the uptake, distribution, and incorporation of phosphorus-32, 2) the metabolism of the individual naphthenic acid, potassium cyclohexanecarboxylate (KCHC), in leaves and roots, and 3) the effect of KNap and KCHC on the uptake and metabolism of glucose by excised root tips. 1) Fourteen-day-old plants growing in a phosphate-free (-P) or a complete (+P) nutrient solution were sprayed to drip with a 0.5% solution of KNap. Twenty-four hours after spraying, the roots of both control and treated plants were exposed for 2 hours to a nutrient solution containing ³²P. Following the exposure to ³²P, the plants were returned to their original nutrient solutions. Control and treated plants were withdrawn 4, 8, 12, and 24 hours after exposure to ³²P, and were separated into leaf blades, stems, and roots. Acid soluble, acid insoluble, and total ³²P activity, or total phosphorus were determined at each sampling time. KNap treatment increased by 7 to 9% the intake of ³²P by plants grown in the -P or +P nutrient solution. The increases, however, lacked statistical significance at the 0.05 level. The rate at which ³²P was translocated out of the roots of plants grown in the -P nutrient only was increased significantly by treatment, in spite of the fact that at the 24 hour sampling time 84% of the total ³²P label remained in root tissues. At the same sampling time 32% of the total ³²P label was found in the roots of plants grown in the +P nutrient. While KNap treatment significantly increased ³²P activity in stems of -P grown plants over the sampling period, activity in stems of control and treated plants grown in the +P nutrient was similar. Naphthenate treatment increased the rate of incorporation of ³²P into both the acid soluble (sugar phosphates, nucleotides, phospholipids) and acid insoluble (nucleic acids, phosphoproteins) fractions of leaves of plants grown in the +P nutrient solution. Acid soluble ³²P activity declined in all root tissues over the sampling period as acid soluble ³²P-containing compounds, primarily orthophosphate, were translocated acropetally. The percentage acid insoluble ³²P activity in the roots of KNap-treated plants was significantly greater than that found in the roots of control plants at the 24 hour sampling time. Naphthenate treatment did not affect the amount of total P (³¹P + ³²P) in the two P fractions of the three plant organs. The augmented incorporation of ³²P into the acid soluble and acid insoluble fractions is further evidence of the KNap-stimulated P metabolism reported by other workers. 2) KCHC-7-¹⁴C administered to leaf disks in the light or to roots of intact seedlings in the dark was rapidly converted to a mixture of two conjugated metabolites: the glucose ester and the aspartic acid amide. The root-feeding experiment indicated that following their synthesis in root tissues both conjugates were translocated acropetally. The results of amino acid analyses of the acid hydrolysates of several unidentified metabolites strongly suggest that KCHC-7-¹⁴C was also conjugated with a low molecular weight polypeptide. 3) Three sets of root tips cut from 7-day-old seedlings were incubated in a medium containing ¹⁴C glucose for 3 hours. Two of the three sets were pretreated in a solution of KCHC or KNap for 6 hours. Each naphthenate treatment significantly increased ¹⁴C activity in the ethanol-soluble (amino acids, glucose, etc.), ethanol-insoluble (polysaccharides, protein, etc.), and respired CO₂ fractions. The individual naphthenic acid, KCHC, had the greater effect on the uptake and metabolism of labelled glucose. Results also indicated that not only were the uptake of glucose and CO₂ production increased significantly by each treatment, but also amino acids containing the glucose carbon passed more quickly through soluble amino acid pools in root tissues, and were more rapidly fixed into protein. In light of the finding that naphthenate conjugates and not the free acid were detected in the tissue, it may be that the conjugates were associated in a causal way with the stimulated uptake and metabolism of labelled glucose. / Science, Faculty of / Botany, Department of / Graduate

Thesis (Ph. D.)--Michigan State University. Plant Breeding and Genetics Program, 2006. / Title from PDF t.p. (viewed on Nov. 12, 2008) Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 179-191). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 179-191). Also available on the Internet.

Please read the abstract in the section 00front of this document. / Dissertation (MSc Agric (Weed Science))--University of Pretoria, 2007. / Plant Production and Soil Science / MSc Agric / unrestricted

Presented as Thesis (Ph. D.)--University of Wisconsin--Madison, 1929. / "Sonderabdruck aus dem Zentralblatt für Bakteriologie, parasitenkunde und Infektionskrankheiten. II. Abteilung. 1929, Bd. 79." Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [38]-39).

The present investigation was undertaken to survey the general features of physiological responses of plants to NO2, and to understand the mechanism of inhibition of gas exchange by NO2. To achieve these objectives, the effects of NO2, on photosynthesis, respiration and transpiration and the rate of NO2, uptake by primary bean (Phaseolus vulgaris. L. cv. 'Pure Gold wax'), leaves were examined in various environmental conditions using an open gas flow system. Apparent photosynthesis, respiration and the evolution of CO2, into CO2- free air, were all inhibited by NO2, concentrations between 1.0 and 7.0 ppm. The degree of inhibition was increased by increasing NO2, concentration and exposure time. A 2 and 5 h exposure to 3.0 ppm NO2, inhibited the gas exchange of bean leaves at all plant ages and in all the environmental conditions examined. Photosynthesis was most inhibited in leaves of intermediate ages, at optimum temperatures, at high light intensities, at relative humidities between 45 and 80% and in leaves of plants grown without any external source of nitrogen. The inhibition was rather less affected by changing C02 or 02 concentration. Maximum inhibition of respiration was observed in the youngest leaves, at high temperatures and in the leaves of nitrogen deficient plants. In most cases, the maximum inhibition of C02 exchange coincided with the maximum control rate in the absence of NO2. The inhibition of transpiration by NO2, was generally small and in a few cases either there was no effect of NO2, on transpiration or it was slightly increased by NO2. This indicated that the primary effects of NO2, were within the leaf mesophyll and not on the stomata. The uptake of N02 was also modified by plant age and environmental conditions. The rate of NO2 uptake increased with increasing concentrations of N02 and decreased with increasing exposure time. It was highest in the leaves of intermediate ages, in the light, at higher temperatures, at low and O2 concentrations, and in nitrogen deficient plants. In most cases, the maximum rate of N02 uptake was correlated with the maximum inhibition of gas exchange, but in several cases, it was not. Although stomatal resistance influenced the rate of N02 uptake to some extent, mesophyll resistance to NO2 was mainly responsible for the regulation of its absorption. In addition to Phaseolus vulgaris L.,10 other angiosperm species were examined. All species absorbed substantial amounts of N02 from an atmosphere of 3.0 ppm NO2, and all experienced a concomitant inhibition of photosynthesis. The rates of N02 uptake and the degree of inhibition varied according to species. The average rate of N02 uptake after a 2 h exposure to 3.0 ppm N02 -2 -1 was 0.391 mg N02 dm h and the average inhibition of photosynthesis with the same dose of N02 was 14.3%. An estimation of N02 uptake on a worldwide basis indicated that a concentration of 0.1 ppm N02 in the world's atmosphere could provide as much as 11% of the total nitrogen requirement of the terrestrial plants. Furthermore, the experiments reveal that the effect of N02 on plant metabolism is not restricted to a particular pathway or process; rather it is generalized. It appears that N02 may inhibit gas exchange by disrupting the structure of cell organelles and/or by interfering with the activities of enzymes. / Land and Food Systems, Faculty of / Graduate

Thesis (M.S.)--Oregon State University, 2011. / Printout. Includes bibliographical references (leaves 116-136). Also available on the World Wide Web.