title: Natural variation for responsiveness to flg22, flgII-28, and csp22 and Pseudomonas syringae pv. tomato in heirloom tomatoes.
abstract: Tomato (Solanum lycopersicum L.) is susceptible to many diseases including bacterial speck caused by Pseudomonas syringae pv. tomato. Bacterial speck disease is a serious problem worldwide in tomato production areas where moist conditions and cool temperatures occur. To enhance breeding of speck resistant fresh-market tomato cultivars we identified a race 0 field isolate, NC-C3, of P. s. pv. tomato in North Carolina and used it to screen a collection of heirloom tomato lines for speck resistance in the field. We observed statistically significant variation among the heirloom tomatoes for their response to P. s. pv. tomato NC-C3 with two lines showing resistance approaching a cultivar that expresses the Pto resistance gene, although none of the heirloom lines have Pto. Using an assay that measures microbe-associated molecular pattern (MAMP)-induced production of reactive oxygen species (ROS), we investigated whether the heirloom lines showed differential responsiveness to three bacterial-derived peptide MAMPs: flg22 and flgII-28 (from flagellin) and csp22 (from cold shock protein). Significant differences were observed for MAMP responsiveness among the lines, although these differences did not correlate strongly with resistance or susceptibility to bacterial speck disease. The identification of natural variation for MAMP responsiveness opens up the possibility of using a genetic approach to identify the underlying loci and to facilitate breeding of cultivars with enhanced disease resistance. Towards this goal, we discovered that responsiveness to csp22 segregates as a single locus in an F2 population of tomato.
authors.affiliation: Department of Horticultural Science, North Carolina State University, Mountain Horticultural Crops Research and Extension Center, Mills River, North Carolina, United States of America.
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Veluchamy
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York, United States of America.
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Hind
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York, United States of America.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Dunham
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York, United States of America; Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Martin
authors.affiliation: Department of Horticultural Science, North Carolina State University, Mountain Horticultural Crops Research and Extension Center, Mills River, North Carolina, United States of America.
authors.forename: Dilip R
authors.initials: DR
authors.lastname: Panthee
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000378:metabolism; D060467:Disease Resistance / Q000276:immunology; D005408:Flagellin / Q000378:metabolism*; D005798:Genes, Bacterial; D014644:Genetic Variation; D007192:Indenes; D018551:Solanum lycopersicum / Q000235:genetics* / Q000276:immunology / Q000382:microbiology*; D009657:North Carolina; D010802:Phylogeny; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D044224:Pseudomonas syringae / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D051192:Receptors, Pattern Recognition / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D007192:Indenes; D051192:Receptors, Pattern Recognition; D005408:Flagellin; C058487:coronatine