Anti-rust coating for plants protects against disease with cellulose nanofiber

A water-absorbent coat to keep rust away? It may seem counterintuitive but when it comes to soybean plants and rust disease, researchers from Japan have discovered that applying a coating that makes leaf surfaces water absorbent helps to protect against infection.

Researchers from the University of Tsukuba have revealed that coating soybean plant leaves with cellulose nanofiber changes the leaf surface from water repellent to water absorbent and offers resistance against Asian soybean rust.

Asian soybean rust (ASR) is an aggressive disease of soybean plants, causing estimated crop yield losses of up to 90%. ASR is caused by Phakopsora pachyrhizi, a fungal pathogen that requires a living plant host to survive. The timely application of fungicide is currently the only way of controlling ASR in the field. But the use of fungicides can be problematic, resulting in negative environmental effects, increased production costs, and fungicide-resistant pathogens.

"We investigated cellulose nanofiber (CNF) as an alternative method of controlling ASR," says senior author of the study, Professor Yasuhiro Ishiga. "Specifically, we wanted to know whether coating soybean plant leaves with CNF protected plants against P. pachyrhizi."

"We showed that CNF can change the soybean leaf surface from hydrophobic to hydrophilic," explains senior author, Professor Yuji Yamashita. "This offers resistance against P. pachyrhizi."