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

Abstract

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 (t1) and beginning of ontogenetic development (t1*). 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 t1*. After ‘swollen bud’, water content raised from ~60 to ~80% at open cluster, while chrysin content decreased and lost its function as an acetylcholinesterase inhibitor. Both parameters can be suitable indicators for t1*. Arabonic acid showed a clear increase after t1*. Pentose acid would be a suitable metabolite to identify t1 and t1*, 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 t1 at t1*. 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.

The Role of Threonine Deaminase/Dehydratase in Winter Dormancy in Sweet Cherry Buds

“…The description of the experimental site, phenological observations in the orchard, determination of ecodormancy phase (t 1 -t 1 *), sampling of sweet cherry buds and preparing for analysis has already been extensively published [1][2][3][4]9,10].…”

“…The mean air temperature ( • C) during the phenophases endodormancy [leaf fall (LF)-end of endodormancy (t 1 )], ecodormancy [t 1 -beginning of ontogenetic development (t 1 *)], and the ontogenetic development, between swollen bud (SB) and side green (SG) was 2.6, 2.8, 4.1, and 6.7 • C, compared to the mean temperature of nine years between 2011/12 and 2019/20 with 5.3, 2.4, 4.5, and 6.7 • C. The FW (Figure 1A-C), DW (Figure 1D-F) and WC (Figure 1G-I) did not significantly change between one week before LF and one week after t 1 *, but was markedly increased at SG (DOY 86) for Summit, Karina and Regina (Figure 1A-I). The beginning of biological activity of the buds was visible in nine seasons by a steady rise of the water content in the buds [10] and was, for Summit, in four out of six seasons, significantly higher seven days after t 1 * [1].…”

“…The FW (Figure 1A-C), DW (Figure 1D-F) and WC (Figure 1G-I) did not significantly change between one week before LF and one week after t1*, but was markedly increased at SG (DOY 86) for Summit, Karina and Regina (Figure 1A-I). The beginning of biological activity of the buds was visible in nine seasons by a steady rise of the water content in the buds [10] and was, for Summit, in four out of six seasons, significantly higher seven days after t1* [1].…”

Wood age, rootstocks and cultivars drive the formation of productivity and fruit size in sweet cherry

“…The influence of rootstocks on the flower induction, and, therefore, precocity and yield, has been studied extensively (Edin et al 1996;Lang 2000;Milić et al 2019). A large share of the research regarding sweet cherry floral organ formation is dedi-cated to framing various stages of reproductive bud development to specific dates and phenological phases of the trees (Guimond et al 1998;Fadón et al 2015), and to investigation of internal processes in the buds during dormancy (Fadón et al 2019;Götz and Chmielewski 2023). Applied studies concerning more practical aspects of productivity formation in relation to wood age, have also been conducted.…”

Stable water isotopes reveal the onset of bud dormancy in temperate trees, whereas water content is a better proxy for dormancy release

“…Sweet cherry tree buds, for instance, typically increase ABA concentration during endodormancy before decreasing it again during ecodormancy, whereas sucrose concentrations steadily increase during endodormancy until maximum concentrations are reached at the beginning of ecodormancy ( Vimont et al. 2021 , Chmielewski and Götz 2022 , Götz and Chmielewski 2023 ). In addition, the activation of inter- and intracell communications through aquaporins seem to play an important role in spring for cells turgescence and bud swelling in deciduous trees ( Yooyongwech et al.…”