Thesis (M.S.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographical references (leaves 54-60). Also available on the World Wide Web.

No description available.

Plant hormone abscisic acid (ABA) plays a main role in coordinating various stress signals in plants. ABA regulates the expression of genes and activities of enzymes in response to various stress conditions. In the following studies we were able to study the ABA mediated regulation of enzymes in plants. Using in-gel activity analysis we identified that ABA regulates the activity of aspartate aminotransferase (AAT), an enzyme involved in nitrogen assimilation and carbohydrate metabolism. Our results indicate that phosphorylation of AAT by SnRK2.2 and 2.3 kinases results in down regulation of AAT2 and AAT3 isozyme activities in Arabidopsis. AAT was identified as a negative regulator of drought stress and aat mutant plants showed improved survival following drought conditions. Using in-gel staining method we were able to visualize sugar phosphatases like fructose 1-6 bisphosphatase family, sedoheptulase-1,7-bisphosphatase, inositol mono phosphatases; protein serine/threonine phosphatases, protein tyrosine phosphatases and studied their response to ABA and drought stress. Fructose-1-6 bisphosphatase family of phosphatases were identified to be induced by ABA in Arabidopsis and rice. N-acetylglucosamine (GlcNAc) is present on glycoproteins and as post translational modification (PTM) in cytoplasmic and nuclear proteins. N-acetylglucosamine is removed from target proteins by hexosaminidases. Little is known about the hexosaminidases in plants. Using in-gel activity analysis we were able to identify an ABA induced Beta-hexosaminidase with a neutral pH optimum in soybean. The nuclear DNA in chromatin is associated with basic proteins called histones. The N-terminal tails of histones contain different PTMs including methylation, phosphorylation, ubiquitination, acetylation, ADP-ribosylation and glycosylation. The histone lysine methylation can serve as a binding site or repel/disrupt the histone binding proteins. The effector/reader proteins specifically recognize the post translational modifications and responsible for the downstream process. Many histone methyl modification effector proteins have been characterized but very few proteins whose binding was disrupted by the presence of a PTM were identified. Using peptide pulldown analysis, far western analyses we identified a WD-40 domain containing histone binding (HB01) protein as direct interactor of unmodified histone. The presence of post translational modifications disrupts HB01 binding to histone H3.

Cuscuta or dodder is one of the best known higher plant parasite with around 158 species over 5 continents parasitising a wide variety of host plants (Yuncker,1932) Dodders are characterised by their interesting parasitic behaviour and extraordinary appearance among the obligate parasitic flowering plants (Kuijt, 1969)

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

PhD by publication.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 190-207) Also available in print.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file plus two media files. Title from title screen of research.pdf file (viewed on May 1, 2009) Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 190-207) Also available online.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references.