Department of Microbiology, Molecular Biology and Biochemistry University of Idaho Moscow, ID 83843-3052   Phone:208-885-9441 Email:acaplan@uidaho.edu   Ph.D. 1980, Department of Zoology (Genetics) University of Iowa     RESEARCH INTERESTS: Metabollic Engineering of Plants for Phytoremediation Novel Biocontrol Agents in Soil Microbial Populations. RESEARCH SUMMARY: Metabolic Engineering of Plants for Phytoremediation. Many areas of the world are heavily contaminated with run-off from mining and industrial sites. These ions can be removed from the environment but only at great expense using a variety of in situ chemical extraction process. The sole alternative to this entire approach uses the natural ability of plants to accumulate free ions and concentrate them internally. Phytoremediation, as this process is called, can be done with for as little as 1/10th of the cost of conventional techniques. The method, however, depends on the capabilities and tolerances of naturally occurring plants. The program in my lab is designed to identify ways to improve the performance of phtoremediative species in order to make this restorative operation more effective. We have been isolating genetic components of the abiotic defenses of rice, a model organism with inherent advantages over many more exotic species for use in phytoremediation. The contributions of two of these genes, called sa/T and rezA, are being studied by manipulating their expression in transgenic plants. A complementary, and possibly more direct approach towards enhancing the accumulation of zinc is to develop new chelating agents to protect parts of the cell that are most sensitive to metal damage. Using what is known about zinc-binding proteins with novel protective characteristics for this purpose. Novel Biocontrol Agents in Soil Microbial Populations Despite extensive use of a variety of control measures, soil nematodes continue to cause crop losses approaching $8 billion dollars annually in this country alone. Many of the chemicals used to control these animals are toxic to both birds and mammals and are not always effective once nematodes have invaded their host. We have isolated a novel soil bacterium that is able to kill the model nematode, Caenorhabditis elegans. By studying how this bacterium kills C. elegans, we hope to uncover toxins capable of killing plant parasitic nematodes. by identifying the host targets affected by the bacterium, we hope to identify proteins that may eventually be targeted by pharmaceuticals capable of affecting nematodes without harming other animals in their ecosystem. Finally, by augmenting the knowledge we now have about this well-studied organism with an examination of its antibacterial defenses, we expect to learn much about the most basic antipathogen defenses in the animal kingdom. REPRESENTATIVE PUBLICATIONS: Caplan, A.B., Van Montagu, M., and Schell, J. 1985. genetic analysis of integration mediated by single T-DNA borders. J. Bacteriol. 161: 655-664 Caplan, A., Berger, Ph.H., and Naderi, M., 1998. Phenotypic variation between transgenic plants: What is making gene expression unpredictabe? In Somaclonal Variation and Induced Mutations in Crop Improvement. S. M. Jain, D.s. Brar, and B.S. Ahloowahia (Eds.), Dorderecht, Kluwer Academic Press. pp. 541-564. Garcia, A. B., de Aleida Engler, J., Iyer, S., Geerts, T., Van Montague, M., andd Caplan A. 1997. Effects of osmoprotechtants upon salt stress in rice. Plant Physiol, 115:159-169. Iyer, S. and Caplan, A. 1998. Products of proline catabolism can function as pleiotopic effectors in rice. Plant Physiol. 116: 203-211. Garcia, A.B., de Aleida Engler, J., Clases, B., Villaroel, R., Van Montague, M., Geerts, T., and Caplan, A. 1998. The expression of the salt-responsive gene salT from rice is regulated by hormonal and developmental cues. Planta 207: 172-180. Cortese, M., Caplan, A., and Crawford, R. 2002. Structural, functional, and evolutionary analysis of moeZ, a gene encoding an enzyme required for the synthesis of the Pseudomonas metabolite, pyridine-2, 6-bis (thiocarboxylic acid). BMC Evolutionary Biology 2: 8 Sripo T, Phongdara A, Wanapu C, Caplan AB. 2002. Screening and characterization of aldehyde dehydrogenase gene from Halomonas salina strain AS11. J Biotechnol 95: 171-179.