Defense Responses to Mycotoxin-Producing FungiFusarium proliferatum, F. subglutinans, andAspergillus flavusin Kernels of Susceptible and Resistant Maize Genotypes

Alessandra Lanubile, Valentina Maschietto, Silvana De Leonardis, Paola Battilani, Costantino Paciolla, Adriano Marocco
2015 Molecular Plant-Microbe Interactions  
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
more » ... ended 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. A. Lanubile and V. Maschietto contributed equally to this work.
doi:10.1094/mpmi-09-14-0269-r pmid:26024441 fatcat:j6bu5qd3wzaonio3ebhzokmduu