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University of Tokyo Professor and Japan International Research Center for Agricultural Sciences Chief Researcher Kazuko Yamaguchi-Shinozaki has developed a genetic modification technology that creates plants resistant to various changes in environmental conditions. Takashi Sasaki reports on this technology that is expected to have applications for increasing food production and, in the future, prevent desertification.
To date, the European Union and countries such as the United States, Russia and Canada have led the world in cereal production, but in recent years South American nations such as Argentina and Brazil have also seen rapid growth in production. However, as such emerging nations are incapable of developing sufficient irrigation facilities in agricultural areas that extend into semi-arid land, large-scale droughts can suddenly occur in years of low rainfall, leading to a cycle in which there is a sharp decrease in the harvest yield once every few years. The genetic modification technology developed by Kazuko Yamaguchi-Shinozaki of the University of Tokyo's Graduate School of Agricultural and Life Sciences has garnered a great deal of global attention as a means of preventing such crop damage.
"Currently, rapid environmental change and abnormal weather is emerging all over the world," Yamaguchi-Shinozaki says. "This has led to the issue of how to stabilize crop harvests. The objective of our research is to resolve this problem using genetic modification."
Through a long evolutionary process since they first began growing on land, plants have developed a tolerance to a range of environmental stresses, such as high and low temperatures and aridity. When Yamaguchi-Shinozaki began her research nearly twenty years ago, about fifty resistance genes that build this tolerance had been identified. The figure now stands as high as 3,000. These genes work in ways such as closing stomata (pores that transpire water), making leaves thicker to store water, and forming special proteins that protect cells from aridity. However, this tolerance is normally inactive inside genes as it can impede plant growth.
This tolerance has to be activated to grow plants with a high resistance to environmental stress. However, to develop strong plants that can survive under various environmental conditions, such as sudden aridity or temperature changes, it is necessary to simultaneously activate all these innate tolerances.
"Genes have components that are like keyholes and can turn this function on and off," Yamaguchi-Shinozaki says. "Because of this, we narrowed our target down to command genes that work on these various resistance genes, or in other words, those genes that play the role of a common key when placed under stress."
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