Metabolites That Confirm Induction and Release of Dormancy Phases in Sweet Cherry Buds

Here we report on metabolites found in a targeted profiling of 'Summit' flower buds for nine years, which could be indicators for the timing of endodormancy release (t(1)) and beginning of ontogenetic development (t(1)*). Investigated metabolites included chrysin, arabonic acid, pentose acid, sucrose, abscisic acid (ABA), and abscisic acid glucose ester (ABA-GE). Chrysin and water content showed an almost parallel course between leaf fall and t(1)*. After 'swollen bud', water content raised from similar to 60 to similar to 80% at open cluster, while chrysin content decreased and lost its function as an acetylcholinesterase inhibitor. Both parameters can be suitable indicators for t(1)*. Arabonic acid showed a clear increase after t(1)*. Pentose acid would be a suitable metabolite to identify t(1) and t(1)*, but would not allow describing the ecodormancy phase, because of its continuously low value during this time. Sucrose reached a maximum during ecodormancy and showed a significant correlation with air temperature, which confirms its cryoprotective role in this phase. The ABA content showed maximum values during endodormancy and decreased during ecodormancy, reaching 50% of its content t(1) at t(1)*. It appears to be the key metabolite to define the ecodormancy phase. The ABA-GE was present at all stages and phases and was much higher than the ABA content and is a readily available storage pool in cherry buds.

Automated summary

In this study, metabolites found in 'Summit' flower buds were analyzed for nine years to identify indicators for the release of endodormancy and the beginning of ontogenetic development. Certain metabolites, including chrysin, arabonic acid, pentose acid, sucrose, abscisic acid (ABA), and abscisic acid glucose ester (ABA-GE), showed significant changes during different stages and phases of bud development. Water content and chrysin were found to be suitable indicators for the beginning of ontogenetic development. Arabonic acid and sucrose played important roles in different phases of dormancy. ABA and ABA-GE were key metabolites for defining the ecodormancy phase and served as readily available storage pools in cherry buds.