Discovery of compounds that suppress plant immune responses

December 15, 2021

New tools for studying plant immune responses

An international research group of RIKEN CSRS, Okayama University and Michigan State University has discovered that tenoxicam, a human nonsteroidal anti-inflammatory drug (NSAID), suppresses plant immune responses.

Salicylic acid, another type of NSAID, acts in plants as an endogenous signaling molecule that enhances resistance against pathogens. However, the underlying mechanisms how salicylic acid activates plant immunity is yet to be fully elucidated.

In this study, the international collaborative research group screened chemical libraries and identified three oxicam-type NSAIDs (tenoxicam, meloxicam, and piroxicam) as an inhibitor of plant immune responses. Furthermore, they showed that tenoxicam induces oxidation of the cytosolic redox status and broadly represses the expression of salicylic acid-dependent genes. The TNX effect highlights the importance of cellular redox balance during SA-dependent signaling.

The results of this study are expected to contribute to the understanding of plant immune mechanisms and the development of new technologies to control disease resistance.


Original article
Nature Communications doi:10.1038/s41467-021-27489-w
N. Ishihama, S. Choi, Y. Noutoshi, I. Saska, S. Asai, K. Takizawa, S. Y. He, H. Osada, K. Shirasu,
"Oxicam-type non-steroidal anti-inflammatory drugs inhibit NPR1-mediated salicylic acid pathway".

Ken Shirasu; Group Director
Nobuaki Ishihama; Research Scientist
Plant Immunity Research Group