Initial plant response mechanism to high temperatures elucidated

January 5, 2016

Potential to contribute to technology development for improved high-temperature stress tolerance

A joint University of Tokyo–RIKEN CSRS research team has elucidated a molecular-level mechanism for high-temperature stress response in plants.

The research group previously found that among the many different heat transcription factors (HSFs) in Arabidopsis, HsfA1 is the master regulator of heat stress response. This time, researchers discovered that the HsfA1 region they tagged as “region 1” actually functions to suppress HsfA1 activity. HsfA1 with region 1 removed (Δ1) constantly had high activity, producing large amounts of HsfA1, and the plants showed high heat stress resilience. However, Δ1 only induced a partial heat stress response, indicating that factors other than HsfA1 are involved in inducing a complete heat stress response. HSP70 was shown to interact with the region 1 and suppress the HsfA1 activity. Repression of HsfA1 by HSP70 may be reduced by heat stress treatment, which activates HsfA1 to induce heat shock proteins.

The HsfA1 regulatory mechanism is conserved in rice and soybean crops. These findings should have applications in the development of crops with high temperature tolerance given the effects of global warming.


Original article
The Plant Cell doi: 10.1105/tpc.15.00435
N. Ohama, K. Kusakabe, J. Mizoi, H. Zhao, S. Kidokoro, S. Koizumi, F. Takahashi, T. Ishida, S. Yanagisawa, K. Shinozaki, K. Yamaguchi-Shinozaki,
"The transcriptional cascade in the heat stress response of Arabidopsis is strictly regulated at the level of transcription factor expression".

Kazuo Shinozaki
Group Director
Gene Discovery Research Group