Transposable elements (transposons) are activated by environmental stress to create stress tolerant plants. The effect by transposition of transposons is controlled by a host plant in some cases. We could verify the importance of transposons existing in the genome of all living creatures.
When Arabidopsis was placed in 37°C for 24 hours, the transposon “ONSEN” was activated because of the high temperature, and an increased number of copies were made within the genome. A stress tolerance test was carried out on this transposed group.
As a result, we could find individuals who demonstrated tolerance to plant hormone abscisic acid stress induced by dormancy, growth suppression, or dry stress.
Through this study on the genome structure of these individuals, we observed insertion of ONSEN in the abscisic acid-responsive gene and found that the mutant became insensitive to stress by gene function destruction.
This study could directly verify that the transposons activated in environmental stress create stress tolerant individuals.
Heat-activated retrotransposon ONSEN is widely found in Brassicaceae plants. By utilizing this artificially activated transposon, cultivation of hardier plant breeding stock is expected.
Assistant Professor Hidetaka ITO
Laboratory of Cell function and Structure III, Biosystems Science Course, Faculty of Science, Hokkaido University