Inhibitory effects of phytic acid on the in vitro and in vivo growth of Trichothecium roseum in apple fruit and the underlying mechanisms involved in its action.

This study evaluated the inhibitory impacts of phytic acid on the growth of T. roseum both in vitro and in apple fruit, as well as elucidated the potential mechanisms underlying its action. Results showed that phytic acid suppressed the lesion diameter caused by T. roseum inoculation in apples, as well as spore germination and mycelial growth of T. roseum in vitro. Phytic acid reduced intracellular conductivity and soluble sugar content, while increasing malondialdehyde and soluble protein contents. Phytic acid treatment inhibited the activities of pectin lyase, pectin methyl polygalacturonase, β-glucosidase, cellulase, xylanase, pectin methyl trans-eliminase, polygalacturonase, and polygalacturonase both in vitro and in apples. In contrast, inoculation of control and phytic acid-treated fruit with T. roseum resulted in increased enzyme activity. These findings suggest that phytic acid decrease the occurrence of heart rot in apples through inducing disruption of the cell membrane of T. roseum and mediating cell wall metabolism.