by Sylvain Comeau
Every year, crops are lost around the world, not only to the usual suspects, pests and disease, but to a little-known culprit: salt. Biology Professor Patrick Gulick believes that genetically engineered plants may be a solution.
Gulick started work on this area of research 14 years ago, as a post-doctoral student at the University of California at Davis. The task he set for himself has entailed arduous long-term research.
"Finding resistance to salinity is difficult, because it's genetically complex," he said. "Many other traits, such as disease resistance, are easy to find by looking at a pattern of inheritance, so you can be sure that a single gene is controlling the trait. But with saline resistance, there are many genes involved.
"At the beginning of our research, we started by looking at genes that are turned on by salt stress, and we found 10 of these." Gulick and his team of graduate students are currently focusing on one particular gene, ESI47, which is found in tall wheat grass, a very salt-tolerant plant.
"ESI47 encodes the protein kinase, which is known to control other proteins, so we thought that this could be a 'switch' -- a mechanism to control the expression of many other genes. We spliced it into a commonly used test plant, Arabadopsis, which is known as the 'white rat' of plant molecular biology."
The genetically altered version of Arabadopsis still has trouble growing in a heavily saline environment, but has responded at a genetic level.
"We don't see salt tolerance in Arabadopsis, but we see that this gene controls one branch of the stress response system in plants. Now that we've accomplished that, we think we can find genes that control the whole system."
The stress response system in tall wheat grass controls not only how the plant survives high salinity, but also its response to drought, cold temperatures, and other factors that can damage plants.
The next step will be to prove that ESI47, or another of the genes Gulick cloned, can transfer stress resistance to Arabadopsis. After that, Gulick will apply for a strategic grant to work on transferring that tolerance to crop species, such as wheat or corn.
"In the past five years, we have discovered that the system of response in tall wheat grass is similar to that in Arabadopsis. What differs between the two species is probably the timing and the degree of gene expression. This discovery may lead to a variety of applications; in many cases, there are wild plant species that don't have agricultural uses, but have very useful genes which can be incorporated into agricultural species." For example, ESI47 could be put into wheat, which is closely related to tall wheat grass.
Gulick expects that the work will progress in leaps and bounds compared to the past, because the technology to analyze genetic data rapidly is now available. It has come to Concordia in the form of the Biotechnology/Bioinformatics Facility for Genomic Research, which was founded last year.
"Now the technology exists to map the response of many genes simultaneously -- which ones turn on, which turn off -- and then look for protein kinases that control parts or all of that response."
Gulick has published five papers on his results in the journal Plant Physiology. His principal collaborators are graduate students Wei Shen and Elizabeth Routley.
Gulick's research is sponsored by NSERC (Natural Sciences and Engineering Research Council) and FCAR (Fonds pour la formation de chercheurs et l'aide ˆ la recherche).