title: Defense Responses to Mycotoxin-Producing Fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in Kernels of Susceptible and Resistant Maize Genotypes.
abstract: Developing kernels of resistant and susceptible maize genotypes were inoculated with Fusarium proliferatum, F. subglutinans, and Aspergillus flavus. Selected defense systems were investigated using real-time reverse transcription-polymerase chain reaction to monitor the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes protective from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) at 72 h postinoculation. The study was also extended to the analysis of the ascorbate-glutathione cycle and catalase, superoxide dismutase, and cytosolic and wall peroxidases enzymes. Furthermore, the hydrogen peroxide and malondialdehyde contents were studied to evaluate the oxidation level. Higher gene expression and enzymatic activities were observed in uninoculated kernels of resistant line, conferring a major readiness to the pathogen attack. Moreover expression values of PR genes remained higher in the resistant line after inoculation, demonstrating a potentiated response to the pathogen invasions. In contrast, reactive oxygen species-scavenging genes were strongly induced in the susceptible line only after pathogen inoculation, although their enzymatic activity was higher in the resistant line. Our data provide an important basis for further investigation of defense gene functions in developing kernels in order to improve resistance to fungal pathogens. Maize genotypes with overexpressed resistance traits could be profitably utilized in breeding programs focused on resistance to pathogens and grain safety.
authors.affiliation: 1Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy;
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lanubile
authors.affiliation: 1Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy;
authors.forename: Valentina
authors.initials: V
authors.lastname: Maschietto
authors.affiliation: 2Dipartimento di Biologia, Università di Bari "Aldo Moro", via E. Orabona 4, 70125 Bari, Italy;
authors.forename: Silvana
authors.initials: S
authors.lastname: De Leonardis
authors.affiliation: 3Istituto di Entomologia e Patologia vegetale, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Battilani
authors.affiliation: 2Dipartimento di Biologia, Università di Bari "Aldo Moro", via E. Orabona 4, 70125 Bari, Italy;
authors.forename: Costantino
authors.initials: C
authors.lastname: Paciolla
authors.affiliation: 1Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy;
authors.forename: Adriano
authors.initials: A
authors.lastname: Marocco
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001231:Aspergillus flavus / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D005670:Fusarium / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D009183:Mycotoxins / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D013482:Superoxide Dismutase; D003313:Zea mays / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology
chemical_list: D009183:Mycotoxins; D010940:Plant Proteins; D006861:Hydrogen Peroxide; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase