Role of CFEM Domain-Containing Protein in Systemic Resistance Induced by <i>Falciphora oryzae</i> to Rice Blast

Abstract

Falciphora oryzae is a newly discovered member of dark septate endophytic fungi, first isolated from wild rice roots. Through symbiosis, it leads to the development of induced systemic resistance of rice against foliar infection caused by Magnaporthe oryzae. However, the mechanism underlying the development of this systemic resistance remains to be elucidated. Here, FoCcw14, a protein containing the CFEM domain, was identified in F. oryzae. By homologous recombination, we obtained the deletion mutant, ΔFoCcw14, which was sensitive to oxidative stresses. Moreover, we showed that FoCcw14 was required for fungal colonization and the generation of immunity when symbiotic with rice. Additionally, FoCcw14 interacted with a germin-like protein, OsGLP2, which is present in the rice apoplast. FoCcw14 promoted the accumulation of OsGLP2 in the host, and then OsGLP2 activated the downstream JA pathway, thereby co-regulating the development of induced systemic resistance.