title: Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides.
abstract: Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.
authors.affiliation: Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, Illinois, 61604, United States of America.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Vaughan
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Alisa
authors.initials: A
authors.lastname: Huffaker
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Schmelz
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Dafoe
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Shawn A
authors.initials: SA
authors.lastname: Christensen
authors.affiliation: Department of Nematology and Entomology, University of Florida, Gainesville, Florida, 32610, United States of America.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: McAuslane
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Hans T
authors.initials: HT
authors.lastname: Alborn
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Leon Hartwell
authors.initials: LH
authors.lastname: Allen
authors.affiliation: Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, Florida, 32608, United States of America.
authors.forename: Peter E A
authors.initials: PE
authors.lastname: Teal
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D055864:Droughts; D037341:Fumonisins / Q000378:metabolism*; D005670:Fusarium / Q000254:growth & development*; D010935:Plant Diseases / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology; D003313:Zea mays / Q000378:metabolism* / Q000382:microbiology*; D000094162:Phytoalexins
chemical_list: D037341:Fumonisins; D010937:Plant Growth Regulators; D012717:Sesquiterpenes; D002245:Carbon Dioxide; D000040:Abscisic Acid; D000094162:Phytoalexins