Show simple item record

dc.contributor.advisorChairperson, Graduate Committee: Michael J. Giroux.en
dc.contributor.authorSchlosser, Alanna Janeen
dc.date.accessioned2013-06-25T18:43:50Z
dc.date.available2013-06-25T18:43:50Z
dc.date.issued2011en
dc.identifier.urihttps://scholarworks.montana.edu/xmlui/handle/1/2202en
dc.description.abstractEfficient allocation of photoassimilates from source to sink tissues is important for optimal plant growth and yield as relative source and sink strength drives growth potential of plant organs. A common method aimed at improving plant yield has been to modify enzymes important to storage compound biosynthesis in sink tissues such as seeds. As the rate limiting step in starch biosynthesis, ADP-glucose pyrophosphorylase (AGPase) has received much attention in this regard. Previously, overexpression of AGPase in seeds resulted in an enhanced yield phenotype in which both plant yield and biomass were increased. However, yield advantages were only observed under nonlimiting environmental resources. The objective of these studies was to 1) determine the importance of native leaf starch levels to the productivity and growth of maize and 2) target source strength by overexpressing AGPase in rice leaves. To determine the importance of native leaf starch levels in maize, field trials of BC 4F 2:3 plants segregating for the presence or absence of the agps-m1 mutation and leaf starch were conducted in Citra, Florida. The results clearly demonstrate the importance of normal leaf starch levels to maize productivity. The starchless agps-m1 plants were 6 to 13 cm shorter, flowered 2 to 3 days later, and had 30 percent lower seed yield than their wild type sisterlines. The impact of increased AGPase in rice leaves was then tested by overexpressing AGPase in rice leaves. Two expression constructs were used to transform rice cultivar Nipponbare, each containing a modified form of the maize endosperm AGPase large subunit sequence, Sh2r6hs, as well as the small subunit sequence, Bt2. Expression of the transgenes was under control of either the rice leaf AGPase small subunit promoter, Ags1, or native rice RuBisCO small subunit promoter, RBC. Expression of the transgenes under the RBC promoter is associated with significantly increased plant biomass. Our results indicate that it is possible to increase plant yield without increasing the rate of photosynthesis. Further, it indicates the possibility of manipulating plant yield through increasing AGPase activity in leaf tissue.en
dc.language.isoenen
dc.publisherMontana State University - Bozeman, College of Agricultureen
dc.subject.lcshCornen
dc.subject.lcshRiceen
dc.subject.lcshStarchen
dc.subject.lcshPhotosynthesisen
dc.subject.lcshCrop yieldsen
dc.titleTransitory leaf starch is an important determinant of plant yielden
dc.typeThesisen
dc.rights.holderCopyright 2011 by Alanna Jane Schlosseren
thesis.catalog.ckey1975266en
thesis.degree.committeemembersMembers, Graduate Committee: Jack Martin; Andreas M. Fischeren
thesis.degree.departmentPlant Sciences & Plant Pathology.en
thesis.degree.genreThesisen
thesis.degree.nameMSen
thesis.format.extentfirstpage1en
thesis.format.extentlastpage52en
mus.relation.departmentPlant Sciences & Plant Pathology.en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record


MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.