A new growth promotion mechanism in times of water deficit

January 11, 2017

Potential contribution to technological development for improving plant growth and crop harvesting in suboptimal conditions

A team of joint researchers at the University of Tokyo and RIKEN CSRS have discovered a novel growth promotion mechanism activated in times of osmotic stress such as arid or saline conditions, clarifying the control mechanism to the molecular level.

Stressed plants are known to accumulate abscisic acid (ABA) and undergo transcriptional activation mediated by ABA-activated Subclass III SnRK2 protein kinases to realize dehydration stress tolerance. There are also some Subclass I SnRK2s activated without ABA in the initial stages of water deficit, but the role of these ABA-unresponsive enzymes remained unclear.

The research group determined that the ABA-unresponsive SnRK2s and their downstream substrate VARICOSE (VCS), an mRNA decapping activator, work to decay unneeded mRNA under water-deficit stress. Since mutants deficient in Subclass I SnRK2s showed growth retardation under osmotic stress, researchers were able to demonstrate that mRNA decay functions work to promote growth in stressed plants.

These findings could contribute to new approaches for improving plant growth and crop yields in stress conditions.

Original article
Nature Plants doi:10.1038/nplants.2016.204
F. Soma, J. Mogami, T. Yoshida, M. Abekura, F. Takahashi, S. Kidokoro, J. Mizoi, K. Shinozaki, K. Yamaguchi-Shinozaki,
"ABA-unresponsive SnRK2 protein kinases regulate mRNA decay under osmotic stress in plants".
Fuminori Takahashi; Research Scientist
Kazuo Shinozaki; Team Leader
Biomass Research Platform Team