Isolation and characterization of a vacuolar Na⁺/H⁺ exchanger in Salicornia bigelovii Torr.
AuthorKshirsagar, Meenakshi K.
AdvisorSchumaker, Karen S.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThe work in this thesis provided critical information about the vacuolar Na⁺/H⁺ exchanger in Salicornia bigelovii with a goal to understand its role in plant salt tolerance. A cDNA (SbNHX1) was isolated and showed 87% identity to the Na⁺/H⁺ exchanger from the glycophyte, Arabidopsis thaliana. DNA blot analysis suggests the presence of a family of Na⁺/H⁺ exchangers in Salicornia bigelovii . An increase in SbNHX1 transcript was seen in shoots of 200 mM NaCl-grown plants compared to transcript levels in 5 mM NaCI-grown plants. To understand whether the SbNHX1 cDNA conferred increased salt tolerance by virtue of its unique sequence, the coding region of SbNHX1 was cloned for expression in Arabidopsis thaliana . Potential Ca⁺² regulation of vacuolar Na⁺/H⁺ exchange is shown using transport experiments. The isolation of a vacuolar Na+/H+ exchanger from Salicornia bigelovii and its functional expression in Arabidopsis thaliana will provide information on the salt tolerance mechanisms used by halophytes. (Abstract shortened by UMI.)
Degree ProgramGraduate College