Amylase and protease inhibition activity against Fusarium verticillioides Amylase and protease inhibition activity against Fusarium verticillioides

Abstract

The primary maize pathogen, Fusarium verticillioides (F. moniliforme Sheldon) is responsible for fumonisin production, which is harmful to human and animal health. In addition, maize can be more susceptible to fungal infection after insect attack. The activity of amylase and protease inhibitors in AG 5011 and CD 307 hybrids were determined during germination with controlled and not controlled conditions of temperature and relative humidity and, they were correlated to maize resistance against Sithophilus zeamais. The inhibitory activity during corn germination was evaluated at 0, 24, 48, 72, 96 and 168 h. Amylase and protease inhibitory activity increased during germination in both hybrids, which ranged respectively from 2.8 to 39.5 UIA/g, and 550.0 to 3633.9 UIP/g. The highest levels of inhibitory activity occurred in hybrid CD 307 in germination chamber. The biologic cycle and susceptible rate were evaluated for corn resistance test. The AG 5011 hybrid was less susceptible to S. zeamais and showed higher inhibitory activity (time 0 h), demonstrating possible relationship between resistance against the insect and inhibitory enzymes. These results indicated that maize natural defense mechanism plays an important role on phytopathogen control.