Mla- and Rom1-mediated control of microRNA398 and chloroplast copper/zinc superoxide dismutase regulates cell death in response to the barley powdery mildew fungus.
• Barley (Hordeum vulgare L.) Mildew resistance locus a (Mla) confers allele-specific interactions with natural variants of the ascomycete fungus Blumeria graminis f. sp. hordei (Bgh), the causal agent of powdery mildew disease. Significant reprogramming of Mla-mediated gene expression occurs upon infection by this obligate biotrophic pathogen. • We utilized a proteomics-based approach, combined with barley mla, required for Mla12 resistance1 (rar1), and restoration of Mla resistance1 (rom1) mutants, to identify components of Mla-directed signaling. • Loss-of-function mutations in Mla and Rar1 both resulted in the reduced accumulation of chloroplast copper/zinc superoxide dismutase 1 (HvSOD1), whereas loss of function in Rom1 re-established HvSOD1 levels. In addition, both Mla and Rom1 negatively regulated hvu-microRNA398 (hvu-miR398), and up-regulation of miR398 was coupled to reduced HvSOD1 expression. Barley stripe mosaic virus (BSMV)-mediated over-expression of both barley and Arabidopsis miR398 repressed accumulation of HvSOD1, and BSMV-induced gene silencing of HvSod1 impeded Mla-triggered H₂O₂ and hypersensitive reaction (HR) at barley-Bgh interaction sites. • These data indicate that Mla- and Rom1-regulated hvu-miR398 represses HvSOD1 accumulation, influencing effector-induced HR in response to the powdery mildew fungus.
Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011-1020, USA.
Weihui
W
Xu
Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011-1020, USA.
Yan
Y
Meng
Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011-1020, USA.|Corn Insects and Crop Genetics Research Unit, US Department of Agriculture-Agricultural Research Service, Iowa State University, Ames, IA, 50011-1020, USA.
Roger P
RP
Wise
D000483:Alleles; D001203:Ascomycota / Q000502:physiology*; D016923:Cell Death; D002736:Chloroplasts / Q000201:enzymology*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D001467:Hordeum / Q000166:cytology* / Q000235:genetics / Q000382:microbiology*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000382:microbiology; D013482:Superoxide Dismutase / Q000378:metabolism*
D035683:MicroRNAs; D010940:Plant Proteins; D012333:RNA, Messenger; D013482:Superoxide Dismutase
Blumeria graminis; barley; hypersensitive reaction; microRNA; reactive oxygen species (ROS); superoxide dismutase (SOD)