Yeast Functional Screen to Determine cDNAs of European Alkali Grass (Puccinellia distans) Conferring Selenium (Se) Toxicity

Selenium (Se), a metalloid, is essential for humans and animals, but its excess causes toxicity in all living organisms, including plants. Studies have shown that some wild plants such as European alkali grass (P. distans) are much more resistant to metal / metalloid toxicity than crop plants are. Identification of related genes in such resistant plants is very important to solve the problems caused by heavy metal toxicity especially. In the present study, the cDNA libraries were prepared from the roots and leaves of P. distans and transformed into yeast (Saccharomyces cerevisiae) cells to be tested against Se stress. The yeast cells were grown on medium containing a toxic dose of sodium selenite (15 mM), and the resistant colonies were determined. The cDNA-induced resistance in the selected colonies was also confirmed by re-transformation and drop tests. The analyzes showed that obtained from roots and leaves, the cDNAs conferring resistance to yeast cells were different from each other. The findings of this study should provide a useful scientific basis for future studies concerning investigation of genes conferring resistance to metal / metaloid toxicity and revealing the resistance mechanism.