Agriculture & Food, Volume 9, 2021

Abstract: The response of polyamines (PAs) and amino acids (AAs) to a sequence of environmental temperature changes {cold (orchard) - warm (controlled temperature of ∼22 °C) - cold (orchard)}, of sweet cherry buds (cv. ‘Summit’) of twigs by gas chromatography-mass spectrometry (GC-MS) analyses was determined. Findings were compared with buds of twigs and buds of trees under natural conditions over six weeks between November and January in northeast Germany. Distinct changes of PA and AA content in the tree buds are evident. The level of PAs/AAs in buds of twigs in the orchard, compared to buds of trees, reveal differences after 21 days, which become much greater with increasing time (after 42 days). A temperature of ∼22 °C led to increasing anabolism, and thus to a several hundred times increase of the PAs/AAs in buds of twigs compared to buds of twigs in the orchard, as well as to the buds of trees after 21 days. When these twigs after 21 days at ∼22 °C were placed in the orchard, a clear decrease - well below the level in the buds of twigs under natural conditions - is apparent after 21 days, suggesting strong catabolic activity and consumption of PAs and most AAs within the buds. Compared to the buds of trees, in the buds of twigs kept for 21 days at ∼22 °C, PA and AA levels increased considerably. After returning these twigs to the orchard for 21 days, some of the PAs, AAs exceeded the level in the buds of trees, whereas others were well below the level of the buds of trees. During winter rest, a phase characterized by no growth and development, and by environmental temperature changes for the buds, the turnover (anabolism/catabolism) of PAs and AAs in sweet cherry buds of twigs and trees is evident.