PRESS RELEASE

In the course of daily research work, there are times when researchers get a different “successful result” than they had been expecting. Of course, there is always the possibility that such a result is overlooked since it does not fit in with other results the researcher has achieved to that point.

Researchers at RIKEN’s Plant Science Center had been using Arabidopsis to investigate how plants control oxidative stress from the effects of reactive oxygen by looking for genes resistant to a herbicide (methyl viologen). Their research pointed to the RMV1gene, and they found that the RMV1 protein transported methyl viologen across the plasma membrane.

This finding in and of itself would be enough, but one of the researchers also noticed that the structure of methyl viologen resembles the structure of polyamines, which are essential bioactive agents in all organisms. In plants, polyamines are involved in morphology and in physiological functions such as differentiation of flower buds, but they also play an important role in stress responses. By examining the absorption capacity of polyamines in Arabidopsis mutants with strengthened RMV1gene function, PSC researchers found that the uptake of polyamines was about three times greater compared with wild-type Arabidopsis, indicating the RMV1 protein was a polyamine transporter. This sudden “inspiration” led to a major research result.    

The results of this research clarified part of the mystery surrounding polyamine transport mechanisms in plants. Further elucidation of the molecular mechanism actions of polyamines in terms of stress responses and senescence should contribute to added stress tolerance and increased yields in crops.

Original article:
“Natural variation in a polyamine transporter determines paraquat tolerance in Arabidopsis.” PNAS, 2012. doi/10.1073/pnas.1121406109
Authors:
Miki Fujita, Yasunari Fujita, Satoshi Iuchi, Kohji Yamada, Yuriko Kobayashi, Kaoru Urano, Masatomo Kobayashi, Kazuko Yamaguchi-Shinozaki, and Kazuo Shinozaki

Plasmamembrane localization of RMV1 protein