Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Michael Persans

Second Advisor

Dr. Matthew Terry

Third Advisor

Dr. Frank Dirrigl


To evaluate metal tolerance conferred by the overexpression of Metal Tolerance Protein 1 (MTP1) in transgenic non-accumulator plants such as Arabidopsis thaliana, a model system was developed in Saccharomyces cerevisiae containing either SfMTP1 cDNA, from the metal tolerant plant Streptanthus farnsworthianus, or SpMTP1 cDNA, from the hyperaccumulator Streptanthus polygaloides. Nonquantitative RT-PCR showed constitutive expression of MTP1 in both plant species. Alignment of SfMTP1 and SpMTP1 protein sequences shows a gap in SpMTP1 in a variable histidine region known to affect metal transport. Disk assays revealed SfMTP1 cDNA imparted greater Ni tolerance to yeast than SpMTP1 cDNA; however, SpMTP1 showed higher Cd tolerance than SfMTP1. No significant difference was found with Co; but both cDNAs made yeast slightly more Zn sensitive. MTP1 histidine-rich regions control metal transport mechanisms, but differences in these regions may be responsible for higher tolerance of specific metals between different Streptanthus species.


Copyright 2013 Elyssa Rae Garza. All Rights Reserved.

Granting Institution

University of Texas-Pan American

Included in

Biology Commons