Revealing the mechanism that enables fungi to penetrate hard plant surfaces

February 13, 2026

A novel polymer in filamentous fungi controls extremely high turgor pressure

An international joint research group, including the RIKEN CSRS and Kanazawa University, identified a pair of new genes required for turgor generation in plant pathogenic fungi (filamentous fungi). The group elucidated that these genes control the turgor pressure required for infection through the biosynthesis of a new polymer.

In this study, the research group focused on specialized infection cells called “appressoria,” which are generated when plant pathogenic fungi (molds) invade into host plants. Appressoria produces one of the strongest turgor, up to about 40 times the air pressure in an auto tire. They protrude hard plant surfaces with their strong power, enabling infection. The group destroyed unknown genes whose expression levels increased when appressoria formed using a genome-editing technique they developed and screened for genes contributing to pathogenicity. Consequently, the researchers identified a pair of secondary metabolite biosynthetic enzymes, PKS2 and PBG13, which are essential for generating turgor pressure. In addition, the research group demonstrated that PKS2 and PBG13 contribute to turgor generation in appressoria through biosynthesizing dihydroxyhexanoic acid (DHHA) monomers into polymers.

The results of this study are expected to deepen understanding of the mechanism of turgor generation in cells and contribute to the development of environment-friendly chemicals for agriculture that disrupt pathogenicity alone.

 

Original article

Science　doi: 10.1126/science.aec9443

N. Kumakura, T. Motoyama, K. Miyazawa, T. Nogawa, J. Pernier, K. Yonehara, M. Sato, Y. Goto, K. Sakai, N. Ishihama, K. Matsumori, P. Gan, K. Toyooka, S. Lévêque-Fort, H. Koshino, T. Fukuma, R. J. O'Connell, K. Shirasu,

"Dihydroxyhexanoic acid biosynthesis controls turgor in pathogenic fungi".

Contact

Ken Shirasu; Group Director
Naoyoshi Kumakura; Senior Research Scientist
Plant Immunity Research Group