Shedding light on how plants choose water or protecting themselves against pathogens

May 29, 2017

Drought, salt or cold causes plants to reduce their water uptake, which is called osmotic stress, and is the greatest harm in agriculture.

Arabidopsis thaliana, used as a model plant in molecular biology research, grows around the world and has more than 1,000 accessions. Because of their adaptability to various environmental conditions, A. thaliana accessions have varying levels of osmotic tolerance, despite being the same species. A collaborative research group from Tokyo University of Agriculture, Nara Institute of Science and Technology, Chiba University and RIKEN CSRS compared hundreds of accession groups collected from around the world, and found that the ACQOS (Acquired Osmotolerance) gene determines the presence or absence of osmotic stress tolerance.

Surprisingly, the researchers also found that ACQOS was identical to VICTR (Nucleotide-binding leucine-rich repeat (NLR) protein), an important gene for plant immune response. A. thaliana with ACQOS had excellent disease resistance but impaired osmotic stress tolerance, while ACQOSdeficient A. thaliana had excellent osmotic stress tolerance but lowered disease resistance. The team's finding made it clear that the presence or absence of the ACQOS gene is a deciding factor in whether a plant "chooses" disease resistance or osmotic resistance.

These findings suggest it is possible to design the stress resistance of plants in an optimal direction by addressing their environmental conditions-for example, improve bacterial resistance with ACQOS in environments such as plant factories where drought conditions are not a factor, or raise ACQOS-deficient plants in fields where dry conditions are common.

Original article
Nature Plants doi:10.1038/nplants.2017.72
H. Ariga, T. Katori, T. Tsuchimatsu, T. Hirase, Y. Tajima, J. E. Parker, R. Alcazar, M. Koornneef, O. Hoekenga, A. E. Lipka, M. A. Gore, H. Sakakibara, M. Kojima, Y. Kobayashi, S. Iuchi, M. Kobayashi, K. Shinozaki, Y. Sakata, T. Hayashi, Y. Saijo, T. Taji,
"NLR locus-mediated trade-off between abiotic and biotic stress adaptation in Arabidopsis".
Kazuo Shinozaki; Group Director, Gene Discovery Research Group
Hitoshi Sakakibara; Group Director, Plant Productivity Systems Research Group