Proteasome maturation factor UMP1 confers broad-spectrum disease resistance by modulating H₂O₂accumulation in rice

Abstract

Crops with broad-spectrum resistance (BSR) to diseases are highly desirable in agricultural production. Identification of BSR loci and dissection of the underlying mechanisms are fundamental for crop resistance breeding. Here, we describe the identification and characterization of a rice UMP1 allele, which confers race-nonspecific BSR against blast pathogen Magnaporthe oryzae. OsUMP1 encodes a proteasome maturation factor that contributes to 26S proteasome abundance and activity in rice. Modulation of OsUMP1 expression leads to proteome changes, particularly affects the amounts and activities of H2O2-degrading enzymes. Consequently, H2O2 accumulation and disease resistance are enhanced in OsUMP1-overexpressing rice but reduced in loss-of-function mutants. Elevation of OsUMP1 expression also promotes rice resistance to foliar pathogens Rhizoctonia solani and Xanthomonas oryzae pv. oryzae and a floral pathogen Ustilaginoidea virens without observable yield penalty. These results indicate a BSR pathway linking the proteasome machinery and H2O2 homeostasis, and provide a candidate gene for balancing BSR and yield traits in rice breeding.

Unraveling Microbial Strategies: Targeting the Plant Ubiquitin - Proteasome Pathway

“…The synchronized formation of diverse proteasome subunits and structures requires the collaborative effort of multiple elements, some of which directly impact the immune response. Take OsUMP1, for instance, a controller of 26S proteasome construction in rice, which enhances universal resistance to Magnaporthe oryzae, regardless of race, by regulating H2O2 concentrations [64]. Moreover, the involvement of the influence of proteasome regulator 1 (PTRE1) also encompasses the degradation of the NLR protein suppressor of npr1-1 constitutive 1 (SNC1), thereby shaping the immune reactions [65].…”

The Plant Ubiquitin–Proteasome System as a Target for Microbial Manipulation

“…The assembly of the different proteasomal subunits and subcomplexes requires the coordinated action of several players, some of which have been shown to be directly involved in immunity. For instance, the rice regulators of the 26S proteasome assembly OsUMP1 mediate non-race-specific resistance against Magnaporthe oryzae by modulating the H 2 O 2 levels (47). Moreover, proteasome regulator 1 (PTRE1) is involved in the degradation of the NLR suppressor of npr1-1 constitutive 1 (SNC1) (126).…”