Plants lose their water as transpiration by stomatal opening, which is governed by guard cells surrounding the stomata. Influx of ions such as K+, Cl-, from neighboring cells into guard cells, and malate synthesis within guard cells increases turgor pressure opening the stomata. Stomata close when K+ and Cl- efflux out, and the cytosolic isoform of NADP ME convert malate to pyruvate. We hypothesize that stomatal closure can be controlled by increased NADP ME activity in guard cells. More than one of the homozygous transgenic Arabidopsis plants that are transformed with a guard cell promoter driving expression of maize NADP ME have been obtained by herbicide screening. Molecular studies have confirmed presence of the transgene in these transformants. Enzyme assays shows higher ME activity in these transformants, indicating an active form of maize ME. Such transgenic plants would help to determine effects of increased ME activity on plant water loss.
","abstract_html":"<p>Plants lose their water as transpiration by stomatal opening, which is governed by guard cells surrounding the stomata. Influx of ions such as K<sup>+</sup>, Cl-, from neighboring cells into guard cells, and malate synthesis within guard cells increases turgor pressure opening the stomata. Stomata close when K<sup>+</sup> and Cl- efflux out, and the cytosolic isoform of NADP ME convert malate to pyruvate. We hypothesize that stomatal closure can be controlled by increased NADP ME activity in guard cells. More than one of the homozygous transgenic <em>Arabidopsis</em> plants that are transformed with a guard cell promoter driving expression of maize NADP ME have been obtained by herbicide screening. Molecular studies have confirmed presence of the transgene in these transformants. Enzyme assays shows higher ME activity in these transformants, indicating an active form of maize ME. Such transgenic plants would help to determine effects of increased ME activity on plant water loss.</p>","abstract_has_math":false,"creators":["Thakur, Pooja"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Open Access Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Dr. Marianne Laporte PhD, Chair","Dr. James VandenBosch PhD, Member","Dr. Daniel Clemans PhD, Member"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2006,"date_issued":"2006-01-01T08:00:00Z","date_published":"2006-01-01T08:00:00Z","updated_at":"2026-07-24T02:16:24Z","subjects":["Plants Transpiration","Plant ecology","Plants Water requirements","Biology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://commons.emich.edu/theses/76","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dr. Marianne Laporte PhD, Chair","Dr. James VandenBosch PhD, Member","Dr. Daniel Clemans PhD, Member"]},{"key":"dc:creator","label":"Author","values":["Thakur, Pooja"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Open Access Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Plants Transpiration","Plant ecology","Plants Water requirements","Biology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://commons.emich.edu/theses/76"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Plants lose their water as transpiration by stomatal opening, which is governed by guard cells surrounding the stomata. Influx of ions such as K+, Cl-, from neighboring cells into guard cells, and malate synthesis within guard cells increases turgor pressure opening the stomata. Stomata close when K+ and Cl- efflux out, and the cytosolic isoform of NADP ME convert malate to pyruvate. We hypothesize that stomatal closure can be controlled by increased NADP ME activity in guard cells. More than one of the homozygous transgenic Arabidopsis plants that are transformed with a guard cell promoter driving expression of maize NADP ME have been obtained by herbicide screening. Molecular studies have confirmed presence of the transgene in these transformants. Enzyme assays shows higher ME activity in these transformants, indicating an active form of maize ME. Such transgenic plants would help to determine effects of increased ME activity on plant water loss.
"]},{"key":"dc:title","label":"Title","values":["Increased expression of NADP malic enzyme in the guard cells of Arabidopsis plants"]}]}],"canonical_facts":{"dc:contributor":["Dr. Marianne Laporte PhD, Chair","Dr. James VandenBosch PhD, Member","Dr. Daniel Clemans PhD, Member"],"dc:creator":["Thakur, Pooja"],"dc:description.abstract":["Plants lose their water as transpiration by stomatal opening, which is governed by guard cells surrounding the stomata. Influx of ions such as K+, Cl-, from neighboring cells into guard cells, and malate synthesis within guard cells increases turgor pressure opening the stomata. Stomata close when K+ and Cl- efflux out, and the cytosolic isoform of NADP ME convert malate to pyruvate. We hypothesize that stomatal closure can be controlled by increased NADP ME activity in guard cells. More than one of the homozygous transgenic Arabidopsis plants that are transformed with a guard cell promoter driving expression of maize NADP ME have been obtained by herbicide screening. Molecular studies have confirmed presence of the transgene in these transformants. Enzyme assays shows higher ME activity in these transformants, indicating an active form of maize ME. Such transgenic plants would help to determine effects of increased ME activity on plant water loss.
"],"dc:identifier":["https://commons.emich.edu/theses/76"],"dc:subject":["Plants Transpiration","Plant ecology","Plants Water requirements","Biology"],"dc:title":["Increased expression of NADP malic enzyme in the guard cells of Arabidopsis plants"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Open Access Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T02:16:24Z"}