Inactivating a β1 subunit of SnRK1 promotes broad-spectrum disease resistance in rice

Abstract

Rice is a staple crop for over half of the worlds population, and its sustainable production is vital to ensure global food security. However, rice is highly susceptible to several devastating fungal diseases1, including blast disease caused by Magnaporthe oryzae, sheath blight by Rhizoctonia solani, false smut by Ustilaginoidea virens, brown spot by Bipolaris oryzae, bakanae by Fusarium fujikuroi, and head blight by F. graminearum. The mechanisms underlying the susceptibility of rice to these fungal diseases remain unclear. Here, we report that the {beta} subunit of SnRK1, SnRK1{beta}1A, confers broad-spectrum susceptibility to these fungal diseases. Our findings reveal that diverse rice fungal pathogens have convergently evolved an effector, Gas2, which interacts with SnRK1{beta}1A to prevent its ubiquitination-mediated degradation and promotes its nuclear translocation. While SnRK1{beta}1A is expressed at low levels in healthy plants, its expression is markedly induced upon fungal infections, facilitating susceptibility by inhibiting SnRK11, the subunit of SnRK1, whose overexpression has been shown to enhance broad-spectrum resistance in rice2. Notably, rice lines with disrupted SnRK1{beta}1A are resistant to multiple fungal diseases without compromising growth and yield in the field. Together, this study demonstrates that broad-spectrum disease resistance in crops can be achieved by disrupting inducible susceptibility genes whose encoded proteins are targeted by effectors conserved in multiple pathogens.