Comparative transcriptomic analysis of peach fruits in common and high
temperature conditions
Abstract
Temperature is a major environmental factor that affects fruit storage,
but the underlying molecular mechanism is poorly understood. Here, the
differences in transcriptome, ethylene production, pulp softening of
postharvest peach fruits were compared between common and high
temperature storage conditions. High temperature storage resulted in a
lower level of ethylene production and a slower fruit softening due to
the decreased expression levels of ethylene biosynthetic genes and
softening related enzymes. The MEKK1-MKK2-MPK4/6 genes had high
expression levels in response to high temperature condition. The
decreased expression of pectinesterase, polygalacturonase, pectate
lyase, pectin methylesterase and the increased expression of expansin
were observed in high temperature treatment. A series of genes related
to membrane stability also showed lower transcription levels, such as
peroxidase, lipoxygenase 3 and superoxide dismutase 1/2. These genes
were co-expressed with different auxin response factors, ethylene
response factors and they composed function modules collectively
correlated to physiological changes. Finally, we proposed a model of the
molecular response mechanism of peach fruit at high temperature which
helps to develop new approaches for maintaining fruit quality during
storage.