SRA

Perennial plants, like fruit trees grown in temperate regions, are characterized by bud dormancy, a rest state that protects the bud from cold during winter. At the same time, these plants have developed a requirement for winter chill for correct flowering. However, winters are becoming increasingly warm in temperate regions, resulting in dramatic effects on the flowering output and therefore crop yield. A compound that successfully compensates for missing winter chill is hydrogen cyanamide, which has been used to synchronize and advance flowering time in a range of commercially important fruit crops. Hydrogen cyanamide also represents a unique tool for researchers to study controlled endodormancy release. Here, we treated dormant sweet cherry flower buds with hydrogen cyanamide, sampling flower buds at different time points after treatment. RNAseq revealed more than 6,000 hydrogen cyanamide-responsive genes. In accordance with these results, hydrogen cyanamide treatment increased the levels of jasmonoyl-isoleucine (JA-Ile) and the cytokinins trans-zeatin riboside (tZR), dihydrozeatin (DZ) and dihydrozeatin riboside (DZR). Furthermore, hydrogen cyanamide affected the expression of antioxidant- and cell wall loosening-associated transcripts. These results suggest a complex mechanism of action for hydrogen cyanamide-induced endodormancy release, including key roles for JA-Ile, zeatin-type cytokinins and hydrogen cyanide. Overall design: 21 samples were analyzed in total, a day 0 sample (before treatment) and then day 1, 3 and 6 after treatment samples for both hydrogen cyanamide (2% Dormex) and control (water) treatment. Every sample was analyzed in three biological replicates.