Plant immunity suppression by an exo-β-1,3-glucanase and an elongation factor 1α of the rice blast fungus

• Published in: Nature communications Vol. 14; no. 1; p. 5491
• Main Authors: Liu, Hang, Lu, Xunli, Li, Mengfei, Lun, Zhiqin, Yan, Xia, Yin, Changfa, Yuan, Guixin, Wang, Xingbin, Liu, Ning, Liu, Di, Wu, Mian, Luo, Ziluolong, Zhang, Yan, Bhadauria, Vijai, Yang, Jun, Talbot, Nicholas J., Peng, You-Liang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07-09-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 14/35; 38/1; 38/22; 38/88; 42/70; 631/250/1933; 631/326/193/2542; 631/326/421; 631/449/2169/2674; 82/111; 82/83; Apoplast; Cell walls; Elongation; Fragments; Fungi; Glucan; Glycosidases; Glycosyl hydrolase; Humanities and Social Sciences; Immune response; Laminarin; Magnaporthe oryzae; multidisciplinary; Pathogens; Plant immunity; Proteins; Rice blast; Science; Science (multidisciplinary); Virulence; β-1,3-Glucan
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41175-z

Fungal cell walls undergo continual remodeling that generates β-1,3-glucan fragments as products of endo-glycosyl hydrolases (GHs), which can be recognized as pathogen-associated molecular patterns (PAMPs) and trigger plant immune responses. How fungal pathogens suppress those responses is often poorly understood. Here, we study mechanisms underlying the suppression of β-1,3-glucan-triggered plant immunity by the blast fungus
Magnaporthe oryzae
. We show that an exo-β-1,3-glucanase of the GH17 family, named Ebg1, is important for fungal cell wall integrity and virulence of
M. oryzae
. Ebg1 can hydrolyze β-1,3-glucan and laminarin into glucose, thus suppressing β-1,3-glucan-triggered plant immunity. However, in addition, Ebg1 seems to act as a PAMP, independent of its hydrolase activity. This Ebg1-induced immunity appears to be dampened by the secretion of an elongation factor 1 alpha protein (EF1α), which interacts and co-localizes with Ebg1 in the apoplast. Future work is needed to understand the mechanisms behind Ebg1-induced immunity and its suppression by EF1α.
Fungal cell walls release β-1,3-glucan fragments that trigger plant immunity. Here, the authors show that a glucanase (Ebg1) of the blast fungus
Magnaporthe oryzae
suppresses plant immunity by hydrolyzing β-1,3-glucan. At the same time, Ebg1 induces plant immune responses that are dampened by a fungal protein that interacts with Ebg1.