The key to producing crops in the desert may be found in the Dead Sea, in a fungus that thrives in the lake where few other organisms survive. Researchers participating in a new international study, led by Haifa University’s Institute of Evolution, have managed to create for the first time a genetic sequence of a particular fungus which grows in salt water, and have been able to understand the evolutionary mechanisms that have allowed the fungus to survive for thousands of years in exceptionally salt-rich climes.
“Aside from theoretical knowledge, as soon as we identify the genes responsible for salt resistance, we can transfer them to wheat, for example, and thus be able to grow wheat in desert areas and other salty environments, which could increase worldwide food production,” says University of Haifa Prof. Eviatar Nevo, who led the study.
The Dead Sea is one of the harshest environments for sustaining life and vegetation on the planet, and until not too long ago, the common perception was that no organism could survive in the waters which contain over 35 percent salt. During the 1930’s, Volkney Elizer discovered tiny bacteria capable of surviving in the Dead Sea. But by the late 1990’s, Haifa University had discovered no less than 77 species of fungi in the Dead Sea, which had managed to develop evolutionary methods for surviving the incredibly salty water. The eurotiom rubrum, the focus of the research, is one of them.
The study, which was published recently in Nature Communication, was conducted by Nevo, along with researchers from the U.S. Energy Department’s Human Genome Research Project, as well as researchers from the University of Bayreuth in Germany. According to the scientists, although the bacteria in the Dead Sea are simple organisms with rather simple genomes, the fungus are much more complex, and deciphering their genetic sequence could lead to transferring their properties to other existing species like wheat or barley.
The researchers also managed to find the 26.2 million units that comprise the genome, and sequence the fungi’s 10,000 genes (for comparison, there are 22,000 genes in the human body). Researchers identified the genetic mechanism that allows the fungi to survive the salt water, which included a high prevalence of genes that regulate salt in the cell, as well as other genes that regulate salt vulnerability and increased presence of amino acids capable of functioning in very acidic conditions.
During the second phase of the study, the researchers attempted to grow the fungi in various concentrations of salt water. It turned out that in salt-free water, the fungi were completely unable to create spores. The fungi were able to produce spores in water with a salt concentration as high as 70 percent, but the optimal concentration for spore production was 30 percent. Once in 20 years, a particularly rainy winter manages to dilute the Dead Sea’s salt concentration slightly, explains Nevo. The fungus managed to adapt to these conditions, producing spores that hibernate until the salt concentration drops enough to develop into fungi, which can create more spores, thus perpetuating the species.
Currently, the researchers are looking to find the specific mechanism created by the fungi, hoping to replicate it in other plants, which would enable them to grow in harsh conditions. According to Nevo, “in order to find these complex mechanisms so that they can be replicated, we must find networks of genes that work together as a whole. We understand how the genes influence one another, and how they can influence other plant species. I hope that within the next decade, we will mange to present results, and advance world agriculture.”
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