| As with all transgenic work, an acceptable cloning vector must first be constructed. If there is a need to express a gene of interest in bacteria such as E. coli, a suitable promoter must be included. The bacteriophage T7 promoter is commonly used but has several disadvantages, including induction with IPTG. In the first part of this study, the chloroplast psbA promoter is shown to have a dramatically higher level of expression in E. coli than the T7 promoter, and without the disadvantages of induction with IPTG.; During previous studies in this lab, it was noted that some heat shocked Arabidopsis plants were darker green than controls one week post-treatment. Ultrastructural modifications, particularly in the chloroplasts, were suspected to be caused by heat stress. This study determined changes in chlorophyll content, cell wall width, and starch content were not significantly altered by heat stress, however, there was an obvious difference in thylakoid organization. Heat shocked plants' chloroplasts contained very organized thylakoid fretworks, little starch accumulation, but increased stromal isolates which were hypothesized to be proteinaceous.; Heat stress is a critical factor limiting agricultural production throughout the world. GABA (gamma-aminobutyrate) accumulates in heat stressed plants and may play a role in overcoming the deleterious effects of heat on plants. Glutamate decarboxylase (GAD) catalyzes the decarboxylation of glutamate, yielding CO2 and GABA. GAD is a calcium-dependent calmodulin-binding protein. The last part of this study was implemented to determine if Arabidopsis containing an additional GAD gene (from petunia) would be heat tolerant than the wild-type, and how results would differ using a GAD gene without the calmodulin-binding domain. |
