Causes of ammonium toxicity in plants are identified

August 24, 2021

Application to development of crops suitable for the anticipated high CO2 environments is expected

A joint research group between Nagoya University, Shimane University, Saitama University, and RIKEN CSRS found that plant growth inhibition (ammonium toxicity) due to the fertilization of high concentrations of ammonium salts (ammonium toxicity) is caused by excessive ammonium assimilation by plastidic glutamine synthetase.

Most plant species absorb nitrates and ammonium salts from their roots and use them as nitrogen nutrient sources. However, recent studies have found that the efficiency of the plants to use nitrates decreases with the increase in atmospheric CO2 concentrations. For this reason, ammonium salts are attracting attention as a source of nitrogen nutrition in the environments with high CO2concentrations anticipated in the future. However, the fertilization of high concentrations of ammonium salts often leads to inhibition of plant growth. Although this phenomenon has long been known as “ammonium toxicity,” its cause has not been identified.

In this study, the group identified a cause of ammonium toxicity. The finding can be applied to the development of crops that can grow well even under the fertilization of high concentrations of ammonium salts (crops useful even under environments with high CO2 concentrations).

 

Original article
Nature Communications doi:10.1038/s41467-021-25238-7
T. Hachiya, J. Inaba, M. Wakazaki, M. Sato, K. Toyooka, A. Miyagi, M. Kawai-Yamada, D. Sugiura, T. Nakagawa, T. Kiba, A. Gojon, H. Sakakibara,
"Excessive ammonium assimilation by plastidic glutamine synthetase causes ammonium toxicity in Arabidopsis thaliana".

Contact
Kiminori Toyooka
Senior Technical Scientist
Mass Spectrometry and Microscopy Unit