The OsWRKY47–OsMYB30/OsWRKY39 module confers both physical and chemical defenses against Magnaporthe oryzae to enhance rice blast resistance

The infection cycle of Magnaporthe oryzae (M. oryzae) in rice typically involves initial invasion through penetration of the leaf epidermis, followed by expansion into neighboring cells. However, few studies have identified single genes that mediate defense against both invasion and expansion. In this study, we demonstrate that OsWRKY47 positively regulates resistance to both stages of M. oryzae infection. Mechanistic analyses indicate that OsWRKY47 transcriptionally activates OsMYB30 during the early stage, thereby enhancing lignin accumulation and strengthening physical barriers against fungal invasion. At later stages, OsWRKY47 represses OsWRKY39 expression, thereby inhibiting M. oryzae expansion. Knockout of OsWRKY39 leads to increased accumulation of stevioside, a metabolite that activates plant immune responses, representing a chemical defense strategy. Structure-function analyses further reveal that a region comprising amino acids 282-288 of OsWRKY47 is crucial for the positive regulation of OsMYB30, whereas the region comprising amino acids 303-333 is essential for repression of OsWRKY39. Collectively, these findings reveal an OsWRKY47-OsMYB30/OsWRKY39 regulatory module that confers resistance to M. oryzae by coordinating physical and chemical defenses to restrict pathogen invasion and expansion. Such coordinated activation of physical and chemical defenses may represent a widespread strategy in plant pathogen responses.