Japanese stride toward genetically modified super plant
June 10, 2016
The two rows in the picture above show the identical plant, arabidopsis, grown under identical conditions. The top row, however, was modified genetically to alter the plant's biological clock, increasing its biomass and resilience significantly.
The results, published by Oxford in the journal Plant & Cell Physiology, dazzled the team of researchers at Japan's RIKEN applied science institute, who said they had made a giant step towards the creation of genetic super plants.
"This was a proof-of-concept study, and I'm satisfied because the data were very beautiful and clearly demonstrate that this approach works," said Norihito Nakamichi, who co-led the work with his colleague Hitoshi Sakakibara at the RIKEN Center for Sustainable Resource Science.
All about the clock
The team had conducted earlier experiments that suggested a molecular mechanism was controlling the biological, or circadian, clock of arabidopsis plants. In those trials, the scientists inhibited specific genes known as pseudo-response regulator (PRR) genes, which resulted in less significant changes to the size and resilience of the plant. When three of the genes were repressed, however, the team observed later flowering (resulting in larger size) and greater adaptability due to noticeable changes to the plant's circadian clock.
This time around, Nakamichi and Hitoshi engineered a modified PRR gene known as PRR5-VP that single-handedly brought about the changes seen in the first experiments involving PRR genes.
The later flowering resulted in a doubling of the plant's biomass, and stress tests showed a dramatic increase in resilience. When exposed to a day of freezing temperatures, all of the control plants died, while only half of the PRR5-VP plants succumbed. When exposed to 16 days of drought, all of the PRR5-VP survived, while nearly all of the control plants were killed.
The team at RIKEN said the implementation of PRR5-VP genes on arabidopsis were only the beginning, citing other avenues for further research.
"In other plants, [these genes] might regulate physiological processes not found in the model species [arabidopsis]," Nakamichi said. "This approach may reveal aspects of the evolution of the biological clock's genetic network."