Barley Rom1 antagonizes Rar1 function in Magnaporthe oryzae-infected leaves by enhancing epidermal and diminishing mesophyll defence.
* Barley (Hordeum vulgare) is a host for Blumeria graminis f. sp. hordei (Bgh), which causes powdery mildew, and for the rice blast pathogen Magnaporthe oryzae. It has previously been shown that Rar1, initially identified in a mutational screen as being required for Mla12-specified Bgh-resistance, also controlled pathogenic growth of M. oryzae in barley. Here, we tested whether the rom1 mutation (restoration of Mla12-specified resistance), which restored resistance against Bgh in a susceptible rar1-2 genetic background, also influences the interaction between barley and M. oryzae. * Disease severity after infection with M. oryzae was analysed on rar1-2 mutants and rar1-2 rom1 double mutants. Microscopy and northern analysis were used to gain insight into cellular and molecular events. * On rar1-2 rom1 double mutant plants, the number of M. oryzae disease lesions was increased in comparison to the wild-type and the rar1-2 mutant which correlated with augmented epidermal penetration. However, a decrease in the lesion diameter, apparently conditioned in the mesophyll, was also observed. * These results highlight the impact of Rom1 in basal defence of barley against different pathogens. Importantly, a tissue-specific function for Rom1 with contrasting effects on epidermal and mesophyll defence was demonstrated.
Zellerhoff
Nina
N
Jansen
Marcus
M
Schaffrath
Ulrich
U
Department of Plant Physiology, RWTH Aachen University, D-52056 Aachen, Germany.
D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant; D001467:Hordeum / Q000166:cytology / Q000235:genetics* / Q000382:microbiology; D054884:Host-Pathogen Interactions / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins; D020082:Magnaporthe / Q000472:pathogenicity*; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010940:Plant Proteins; C499582:Rar1 protein, Hordeum vulgare