Increased levels of IAA are required for system 2 ethylene synthesis causing fruit softening in peach (Prunus persica (L). Batsch). Prunus persica

The fruit of melting-flesh peach cultivars produce high levels of ethylene caused by high expression of PpACS1, resulting in rapid fruit softening at the late-ripening stage. In contrast, the fruit of stony hard peach cultivars do not soften and produce little ethylene due to low expression of PpACS1. To elucidate the mechanism for suppressing PpACS1 expression in stony hard peaches, a microarray analysis was performed. Several genes that displayed similar expression patterns as PpACS1 were identified and shown to be IAA-inducible genes. Overall design: Change in gene expression according to growth of fruits in 'melting peach ‘Akatsuki’ fruit sampled at 92, 98, 104 and 106 day after full bloom (DAB). Propylene induced gene expression stony peach ‘Manami’ and ‘Odoroki’ harvested at commercial maturity (Tatsuki et al., 2006).