The distribution of Photosystems (PS) I and II was studied in the green alga Chlamydomonas reinhardtii and compared to that found in the higher plant Pisum sativum. Two antibodies were used; one, anti-CP1-e, was raised against the two reaction center proteins of PS I from Synechococcus elongatus, and the other, anti-CP40, was raised against the 40 kDa protein of PS II from the same organism. Immunogold labelling of C. reinhardtii sections showed that both appressed and non-appressed thylakoid membranes were labelled by each antiserum, with labelling on the non-appressed membranes being somewhat (1.7-1.8 times) higher than that on the appressed membranes. / In P. sativum, anti-CP1-e labelling was 3.9 times higher on the non-appressed membranes than on the appressed ones, whereas anti-CP40 labelling was equally concentrated on both classes of membranes. The data show that PS distribution in C. reinhardtii is similar to that reported for other algae and different from that in higher plants.

The distribution of photosystem I (PS I) and photosystem II (PS II) in a primitive green alga Tetraselmis subcordiformis, which belongs to Prasinophyceae and does not have grana in its chloroplast, was studied by immunoelectron microscopy. Two PS I antibodies were used: one against a PS I component of maize, the other against the 60 and 62 KDa PS I reaction centre proteins of the cyanobacterium Synechococcus elongatus. Both antibodies showed that 76-78% of the labelling is on the appressed thylakoid membranes and only 22-24% is located on the unappressed membranes. Use of antiserum against cp-47 of PS II from S. elongatus also gives 76% of the labelling on appressed thylakoid membranes and 24% on unappressed thylakoid membranes. Cytochemical detection of PS I activity by the photooxidation of 3,3$ sp prime$-diaminobenzidine and of PS II activity by the photoreduction of distyryl nitroblue tetrazolium chloride also revealed that PS I and PS II activities exist on both types of thylakoid membranes. Therefore, our results indicate that the distribution of PS I and PS II in green algae may differ from that in higher plants.

To study the short-term effect of hydrogen peroxide on plant metabolism aminotriazole (2 mM), a catalase inhibitor was applied through the transpiration stream of pea seedlings and the gas exchange characteristics, ascorbate peroxidase, glutathione reductase and catalase activities, and the levels of hydrogen peroxide, glutathione and formate were determined. CO2 assimilation rates were inhibited after the addition of aminotriazole: photorespiratory conditions (high 02 and low CO2 concentrations, high light intensities) exascerbated the inhibition. CO2 response curves showed that aminotriazole reduced both the RuBP regeneration rate and the efficiency of the carboxylation reaction of Rubisco. The inhibition of the CO2 assimilation rate during the first 100 minutes after the addition of aminotriazole was alleviated by feeding PGA through the transpiration stream. Catalase activity was completely inhibited within 200 minutes of aminotriazole application, but there was no concomitant increase in the hydrogen peroxide concentration, suggesting that hydrogen peroxide is metabolised by an alternative mechanism. The treatment had no effect on ascorbate peroxidase and glutathione reductase activities or total glutathione pool size, but greatly increased formate levels. These results suggest that hydrogen peroxide is metabolised by reacting with glyoxylate to form formate and CO2, The increased production of formate may reduce the flow of carbon through the normal photorespiratory pathway and may be used anapleurotically as a precursor of products of l-C metabolism other than serine. This would prevent the return of photorespiratory carbon to the BensonCalvin cycle in the form of 3-PGA. It is proposed that when RuBP regeneration levels are low high formate levels may be an effector of Rubisco, and competitively inhibit the binding of CO2 and 02. These results suggest that under photorespiratory conditions the uninterrupted flow of carbon through the photorespiratory pathway is fundamental to the functioning of photosynthetic metabolism. / Thesis (M.Sc.)-University of Natal, Durban, 1990.

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"May 1958." / Includes bibliographical references (leaves 162-167). / Includes reprint of article co-authored by the author at back: Sodium as an essential micro-nutrient element for Atriplex vesicaria, Heward / P.F. Brownell, J.G. Good. Reprinted from Nature, vol. 179, pp. 635-636, March 23, 1957 / iv, 167 leaves : ill. ; 27 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 Botany, 1958

Thesis (Ph. D. in botany)--Washington State University, May 2008. / Includes bibliographical references.

Thesis (Ph.D.)--Murdoch University, 2006. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 110-127.

Thesis--Helsingfors. / "The object of the present work was to study the transformations which different sugars undergo in living plant tissue, independently of the photosynthetic process."--Summary, p. [98]. On cover: Reprinted from Annales Academias scientiarum fennicae. Series A. Tom. XLIV, no: 8. Bibliography: p. [101]-105.

Thesis (MSc)--University of Stellenbosch, 2008. / Bibliography. Also availabe via the Internet.