title: Differential effects of lesion mimic mutants in barley on disease development by facultative pathogens.
abstract: Lesion mimic mutants display spontaneous necrotic spots and chlorotic leaves as a result of mis-regulated cell death programmes. Typically these mutants have increased resistance to biotrophic pathogens but their response to facultative fungi that cause necrotrophic diseases is less well studied. The effect of altered cell death regulation on the development of disease caused by Ramularia collo-cygni, Fusarium culmorum and Oculimacula yallundae was explored using a collection of barley necrotic (nec) lesion mimic mutants. nec8 mutants displayed lower levels of all three diseases compared to nec9 mutants, which had increased R. collo-cygni but decreased F. culmorum disease symptoms. nec1 mutants reduced disease development caused by both R. collo-cygni and F. culmorum. The severity of the nec1-induced lesion mimic phenotype and F. culmorum symptom development was reduced by mutation of the negative cell death regulator MLO. The significant reduction in R. collo-cygni symptoms caused by nec1 was completely abolished in the presence of the mlo-5 allele and both symptoms and fungal biomass were greater than in the wild-type. These results indicate that physiological pathways involved in regulation of cell death interact with one another in their effects on different fungal pathogens.
authors: Present address: Crop Protection Team, Crop and Soil Systems Group, SRUC, West Mains Road, Edinburgh, EH9 3JG, UK graham.mcgrann@sruc.ac.uk james.brown@jic.ac.uk.
authors: Graham R D
authors: GR
authors: McGrann
authors: Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK Present address: Crop Protection Team, Crop and Soil Systems Group, SRUC, West Mains Road, Edinburgh, EH9 3JG, UK Present address: RAGT Seeds Ltd., Grange Road, Ickleton, Essex, CB10 1TA, UK.
authors: Andrew
authors: A
authors: Steed
authors: Present address: RAGT Seeds Ltd., Grange Road, Ickleton, Essex, CB10 1TA, UK.
authors: Christopher
authors: C
authors: Burt
authors: Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK Present address: Crop Protection Team, Crop and Soil Systems Group, SRUC, West Mains Road, Edinburgh, EH9 3JG, UK Present address: RAGT Seeds Ltd., Grange Road, Ickleton, Essex, CB10 1TA, UK.
authors: Paul
authors: P
authors: Nicholson
authors: Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK Present address: Crop Protection Team, Crop and Soil Systems Group, SRUC, West Mains Road, Edinburgh, EH9 3JG, UK Present address: RAGT Seeds Ltd., Grange Road, Ickleton, Essex, CB10 1TA, UK graham.mcgrann@sruc.ac.uk james.brown@jic.ac.uk.
authors: James K M
authors: JK
authors: Brown
mesh_terms: D000483:Alleles; D001203:Ascomycota / Q000502:physiology*; D016923:Cell Death; D060467:Disease Resistance; D005670:Fusarium / Q000502:physiology; D001467:Hordeum / Q000235:genetics / Q000276:immunology* / Q000382:microbiology / Q000502:physiology; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology*; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins
keywords: Cell death; disease resistance; endophyte; hemibiotroph; hypersensitive response; mlo; necrotroph; plant-microbe interactions.