title: Resistance to Fusarium verticillioides and fumonisin accumulation in maize inbred lines involves an earlier and enhanced expression of lipoxygenase (LOX) genes.
abstract: Fusarium verticillioides causes ear rot in maize and contaminates the kernels with the fumonisin mycotoxins. It is known that plant lipoxygenase (LOX)-derived oxylipins regulate defence against pathogens and that the host-pathogen lipid cross-talk influences the pathogenesis. The expression profiles of fifteen genes of the LOX pathway were studied in kernels of resistant and susceptible maize lines, grown in field condition, at 3, 7 and 14 days post inoculation (dpi) with F. verticillioides. Plant defence responses were correlated with the pathogen growth, the expression profiles of fungal FUM genes for fumonisin biosynthesis and fumonisin content in the kernels. The resistant genotype limited fungal growth and fumonisin accumulation between 7 and 14 dpi. Pathogen growth became exponential in the susceptible line after 7 dpi, in correspondence with massive transcription of FUM genes and fumonisins augmented exponentially at 14 dpi. LOX pathway genes resulted strongly induced after pathogen inoculation in the resistant line at 3 and 7 dpi, whilst in the susceptible line the induction was reduced or delayed at 14 dpi. In addition, all genes resulted overexpressed before infection in kernels of the resistant genotype already at 3 dpi. The results suggest that resistance in maize may depend on an earlier activation of LOX genes and genes for jasmonic acid biosynthesis.
authors.affiliation: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy. Electronic address: valentina.maschietto@unicatt.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Maschietto
authors.affiliation: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy. Electronic address: adriano.marocco@unicatt.it.
authors.forename: Adriano
authors.initials: A
authors.lastname: Marocco
authors.affiliation: Christian Doppler Laboratory for Mycotoxin Metabolism and Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Str. 20, 3430 Tulln, Austria. Electronic address: alexandra.malachova@boku.ac.at.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Malachova
authors.affiliation: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy. Electronic address: alessandra.lanubile@unicatt.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lanubile
mesh_terms: D037341:Fumonisins / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005670:Fusarium / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D008084:Lipoxygenase / Q000235:genetics* / Q000378:metabolism; D009183:Mycotoxins / Q000378:metabolism*; D000069600:Plant Breeding; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*
chemical_list: D037341:Fumonisins; D005656:Fungal Proteins; D009183:Mycotoxins; D010940:Plant Proteins; D008084:Lipoxygenase
keywords: Fumonisin; Fusarium verticillioides; Lipoxygenase genes; Pathogen resistance; Zea mays