mlo-based powdery mildew immunity: silver bullet or simply non-host resistance?
SUMMARY Durability and effectiveness against all genetic variants of a microbial species are hallmarks of so-called plant 'non-host' resistance. Highly effective immunity of monocotyledonous barley against the fungal powdery mildew pathogen, which is conferred by loss-of-function mutant alleles of the barley Mlo locus, likewise is a durable and broad-spectrum type of resistance. Although this was long considered as being a barley-specific phenomenon, recent findings indicate that mlo resistance can also occur in the distantly related dicotyledonous species Arabidopsis thaliana. Shared histological and phytopathological characteristics plus a conserved requirement for a set of genes in Arabidopsis mlo and non-host powdery mildew resistance indicate a potential common mechanism for these two seemingly distinct types of immunity.
Humphry
Matt
M
Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
Consonni
Chiara
C
Panstruga
Ralph
R