GSE128158
Transcriptome analysis in buds of peach trees treated with hydrogen cyanamide that advanced bud break
To determine how dormancy breaking agent, hydrogen cyanamide (HC) advances bud break in peach (Prunus persica), this research compared the transcriptome of buds of low-chill 'TropicBeauty' peach trees treated with 1% (v/v) HC and that of non-treated trees at 3 and 7 days after treatment (DAT), respectively, using RNA sequencing analysis. The peak of total bud break occurred 6 weeks earlier in the HC treated trees (at 32 DAT) than the non-treated trees (at 74 DAT). There were 1312 and 1095 differentially expressed genes (DEGs) at 3 and 7 DAT, respectively. At 3 DAT, DEGs related to oxidative stress, including response to hypoxia, lipid oxidation, and reactive oxygen species (ROS) metabolic process, were up regulated in HC-treated buds. Additionally, DEGs encoding enzymes for ROS scavenging and pentose phosphate pathway were up regulated at 3 DAT but were not differently expressed at 7 DAT, indicating a temporary demand for defense mechanisms against HC-triggered oxidative stress. Up regulation of DEGs for cell division and development at 7 DAT, which were down regulated at 3 DAT, suggests cell activity was initially suppressed but enhanced within 7 days following the treatment. At 7 DAT, DEGs related to cell wall degradation and modification were up-regulated, possibly responsible for the burst of buds. The results of this study strongly suggest that HC induces transient oxidative stress shortly after application leading to the release of bud dormancy and, subsequently, causes an increase in cell activity and cell wall loosening, thereby accelerating bud break in peach. Overall design: Samples (bud tissue) of 'TropicBeauty' peach trees treated with 1% (v/v) hydrgen cyanamide (HC) and non-treated control trees at 3 and 7 day after treatment; each sample was analyzed in four biological replicates.