Powdery mildew (PM) caused by Podosphaera leucotricha is a major fungal
disease of thousands of plants, including many cultivated Rosaceae species.
PM pathogenesis is associated with up-regulation of MLO genes during early
stages of infection. The genes' upregulation causes decrease in plant
defense. MLO gene family can act as susceptibility genes, since
down-regulation of these genes may grant plant resistance.

The Fondazione Edmund Mach in Italy carried out an analysis of the MLO genes
in apple, peach, and strawberry. The researcher identified candidate PM
susceptibility genes through studying their relationships with other
characterized MLO genes. In apple, susceptibility genes were inferred by
monitoring their expression following inoculation with Podosphaera
leucotricha.

Genomic tools available for Rosaceae family were exploited to identify the
candidate MLO susceptibility genes. In follow-up studies it can be
investigated whether silencing in one or more of these candidate genes leads
to PM resistance.

[www.biomedcentral.com]