Thesis (Ph. D.)--University of Wisconsin, 1964. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 107-113.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1953. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-58).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1942. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-106).

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 78-80).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1928. / Typescript. With this is bound: The known predacious and parasitic enemies of the pea aphid in North America / C.L. Fluke. (Research bulletin / University of Wisconsin, Agricultural Experiment Station ; 93), 47 p. Includes bibliographical references (leaves 93-96).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 211-227).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. Includes tables. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Master of Science / Biochemistry / Gerald Reeck / Laccases belong to the “multicopper oxidase” family of proteins, and can oxidize o-diphenols and p-diphenols in the presence of molecular oxygen. Laccases have been well characterized in wood-rotting fungi where they appear to play a role in lignin degradation, morphogenesis, and stress defense. More recently, laccase-2 has been found to play a role in the insect cuticle sclerotization and tanning. In addition, it has been hypothesized that laccase-1 may be involved in the oxidation of toxic phenolic compounds ingested by insects during feeding. A laccase-type phenoloxidase has been identified in the pea aphid, Acyrthosiphon pisum (Harris) using a combination of substrates that react with laccase. Within the pea aphid, laccase-1 transcript was found to be localized within the gut and the salivary glands. Finally, the specific regions where laccase-1 was present in the salivary gland was visualized using immunohistochemistry.

No description available.

Bird cherry-oat aphid (Rhopalosiphum padi L.) is an important pest on spring-sown cereals. The aphid reduces yield and can act as a vector of barley yellow dwarf virus. R. padi does not give visible symptoms, but heavy infestation can reduce the yield substantially. R. padi is one of the most important pests of barley, which has the fourth rank among the cereals in global production. In order to overcome this problem, the plants are treated with pesticides. However, some of the pesticides are no longer permitted to use due to their negative environmental effects. Another problem is that the aphids develop resistance against them. Therefore, a new approach is to identify genetic factors that could be used in breeding host plants for resistance. There are many examples of successful plant breeding for resistance to aphids, but in the case of R. padi and barley, no resistant cultivar is commercially available. The aim of this thesis was to identify and characterise aphid resistance and susceptibility factors in barley. This was done using two major approaches. Firstly, constitutive and aphid-induced gene expression was studied in a large number of barley genotypes with known levels of resistance. Secondly, two cDNAs putatively adding to aphid resistance were transformed to Arabidopsis and barley and the effect of transformation on aphid performance and behaviour was evaluated.      The study of constitutive transcript abundance in 23 barley genotypes gave suggestive evidence that two genes might be related to aphid resistance; a thionin and a proteinase inhibitor gene, and that a lipoxygenase gene might be related to aphid susceptibility.The study of both constitutive and aphid-induced transcript abundances of three glucanase genes, gave support to the idea that two of them might be susceptibility factors. The cDNA of the proteinase inhibitor mentioned above was expressed in Arabidopsis, under control of either a constitutive or a phloem-specific promoter and the effects were evaluated using the green peach aphid, Myzus persicae Sulzer. This aphid is a generalist, feeding on many different plant species, both monocot (such as barley) and dicot (such as Arabidopsis).  The results showed lower settling and fecundity on some of the transgenic lines as compared to on controls.        In conclusion, the thesis suggests a role in resistance against R. padi in barley for two genes encoding a thionin and a proteinase inhibitor. It has also given support for a role in susceptibility against R. padi of genes encoding a lipoxygenase and two glucanases. The work further shows that a cDNA from barley, selected based on the interaction between a monocot plant and an essentially monocot specialist aphid, affected the resistance of the dicot Arabidopsis against a generalist aphid. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>