Mechanism of plants to switch between growth and stress responses

July 21, 2021

Expected to create crops with high growth capacity and strong environmental stress tolerance

A joint research group led by Tokyo University of Agriculture and Technology, RIKEN CSRS, Utsunomiya University, and Saitama University has revealed a part of the mechanism by which plants placed in poor environments switch their growth strategies and maximize their ability to adapt to environmental stresses.

In mild environmental conditions suitable for growth, it is more advantageous for plants to accelerate growth as much as possible. On the other hand, under water-deficient stress conditions such as desiccation and salt damages, a plant hormone “abscisic acid (ABA)” accumulates at a high level, and growth is suppressed. When that occurs, SnRK2, a type of protein kinase, is activated and various substrate proteins are phosphorylated to induce stress tolerance. The research group identified Raf36 kinase as a novel substrate protein that is phosphorylated into SnRK2 kinases. They also found that the SnRK2-Ra36 complex regulates the balance and switching between “promoting growth in favorable growth environments” and “enhancing ABA response in unfavorable environments” in plants.

The results of this study can be applied to develop crops that show both high growth capacities and strong environmental stress tolerance even under unfavorable environmental conditions.

Original article
Proceedings of the National Academy of Sciences of the USA(PNAS) doi:10.1038/10.1073/pnas.2100073118
Y. Kamiyama, M. Hirotani, S. Ishikawa, F. Minegishi, S. Katagiri, C. J. Rogan, F. Takahashi, M. Nomoto, K. Ishikawa, Y. Kodama, Y. Tada, D. Takezawa, J. C. Anderson, S. C. Peck, K. Shinozaki, T. Umezawa,
"Arabidopsis Group C Raf-like protein kinases negatively regulate abscisic acid signaling and are direct substrates of SnRK2".
Kazuo Shinozaki
Group Director
Gene Discovery Research Group