Effect of Auxin on ethylene biosynthesis of peach fruit ripening

由于PpACS1的低表达，石硬桃品种的果实不软化，产生的乙烯较少。溶肉桃收获前IAA浓度突然升高。相反，IAA浓度在石硬桃中没有增加。这些结果表明，石硬桃成熟后期PpACS1表达的抑制可能是由于IAA水平较低所致，而在桃体内产生大量的system 2乙烯需要高浓度的IAA。

The fruit of stony hard peach cultivars do not soften and produce little ethylene due to low expression of PpACS1. The IAA concentration increased suddenly just before harvest time in melting flesh peaches. In contrast, the IAA concentration did not increase in stony hard peaches. These observations indicate that suppression of PpACS1 expression at the late-ripening stage of stony hard peach may result from a low level of IAA, and a high concentration of IAA is required to generate a large amount of system 2 ethylene in peaches.