PT  - JOURNAL ARTICLE
AU  - Haruka Saito
AU  - Yuji Yamashita
AU  - Nanami Sakata
AU  - Takako Ishiga
AU  - Nanami Shiraishi
AU  - Viet Tru Nguyen
AU  - Eiji Yamamura
AU  - Yasuhiro Ishiga
TI  - Covering soybean leaves with cellulose nanofiber changes leaf surface hydrophobicity and confers resistance against <em>Phakopsora pachyrhizi</em>
AID  - 10.1101/2020.08.26.267807
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.08.26.267807
4099  - http://biorxiv.org/content/early/2020/08/27/2020.08.26.267807.short
4100  - http://biorxiv.org/content/early/2020/08/27/2020.08.26.267807.full
AB  - Asian soybean rust (ASR) caused by Phakopsora pachyrhizi, an obligate biotrophic fungal pathogen, is the most devastating soybean production disease worldwide. Currently, timely fungicide application is the only means to control ASR in the field. We investigated cellulose nanofiber (CNF) application on ASR disease management. CNF-treated leaves showed reduced lesion number after P. pachyrhizi inoculation compared to control leaves, indicating that covering soybean leaves with CNF confers P. pachyrhizi resistance. We also demonstrated that formation of P. pachyrhizi pre-infection structures including germ-tubes and appressoria, and also gene expression related to these formations, such as chitin synthases (CHSs), were significantly suppressed in CNF-treated soybean leaves compared to control leaves. Moreover, contact angle measurement revealed that CNF converts soybean leaf surface properties from hydrophobic to hydrophilic. These results suggest that CNF can change soybean leaf surface hydrophobicity, conferring resistance against P. pachyrhizi, based on the reduced expression of CHSs, as well as reduced formation of pre-infection structures. This is the first study to investigate CNF application to control field disease.Competing Interest StatementThe authors have declared no competing interest.