Project description:A grape-bud-oriented genomic platform was produced for a large-scale comparative analysis of bud responses to two stimuli of grape-bud dormancy release, hydrogen cyanamide (HC) and heat shock (HS). The results suggested considerable similarity in bud response to the stimuli, both in the repertoire of responding genes and in the temporary nature of the transcriptome reprogramming. Nevertheless, the bud response to HC was slower, more condensed and stronger, as reflected by a higher number of regulated genes and a higher intensity of regulation compared to the response to HS. To facilitate large-scale comparative analysis of early changes in the bud transcriptome by cDNA microarray, HC and HS were applied to canes collected from three vineyards, located in different regions, in three different years. This experimental scheme resulted in two true biological replicates for each treatment, differing in both timing and location, and loop design of technical replicates within time series. Consistent with our previous studies, both application of 5% Dormex (HC) and incubation for 1 h in 50oC water (HS) resulted in increased bud-break rates compared to respective controls. Bud break of HS-treated and HC-treated buds started 10 to 12 days after treatment. Three weeks after treatment, HS-treated buds exhibited 100% bud break while HC-treated buds had reached 80% bud break. The control showed significantly lower levels of bud break during this period. Bud material was collected from control, HC- and HS-treated cuttings at six time points (3, 6, 12, 24, 48 and 96 h) after the treatments and used to prepare total RNA samples.
Project description:Hydrogen cyanamide (HC) is an agrochemical compound frequently used to break bud dormancy in grapevine grown under mild winter conditions all over the world. The present study was carried out to get a better understanding of the molecular mechanism associated with HC to release bud dormancy in grapevine using RNA-seq based transcriptomic and tandem mass tag (TMT) based proteomic analysis.
Project description:Correlation analysis of the expression of bud dormancy-related genes in 10 peach cultivars, with different chilling requirements for dormancy release.
Project description:Bud dormancy is a crucial stage in perennial trees and allows survival over winter and optimal subsequent flowering and fruit production. Environmental conditions, and in particular temperature, have been shown to influence bud dormancy. Recent work highlighted some physiological and molecular events happening during bud dormancy in trees. However, we still lack a global understanding of transcriptional changes happening during bud dormancy. We conducted a fine tune temporal transcriptomic analysis of sweet cherry (Prunus avium L.) flower buds from bud organogenesis until the end of bud dormancy using next-generation sequencing. We observe that buds in organogenesis, paradormancy, endodormancy and ecodormancy are characterised by distinct transcriptional states, and associated with different pathways. We further identified that endodormancy can be separated in two phases based on its transcriptomic state: early and late endodormancy. We also found that transcriptional profiles of just 7 genes are enough to predict the main cherry tree flower buds dormancy stages. Our results indicate that transcriptional changes happening during dormancy are robust and conserved between different sweet cherry cultivars. Our work also sets the stage for the development of a fast and cost effective diagnostic tool to molecularly define the flower bud stage in cherry trees.
Project description: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.
Project description:A grape-bud-oriented genomic platform was produced for a large-scale comparative analysis of bud responses to two stimuli of grape-bud dormancy release, hydrogen cyanamide (HC) and heat shock (HS). The results suggested considerable similarity in bud response to the stimuli, both in the repertoire of responding genes and in the temporary nature of the transcriptome reprogramming. Nevertheless, the bud response to HC was slower, more condensed and stronger, as reflected by a higher number of regulated genes and a higher intensity of regulation compared to the response to HS.
Project description:Microarray analysis revealed specific alterations in gene expression in dormancy breaking buds induced by pruning (P), hydrogen cyanamide (HC), pruning plus hydrogen cyanamide (PHC) after 24 h of treatment. PHC treatment altered the expression of the largest number of genes and rapid accumulation of a sublethal level of reactive oxygen species and reactive nitrogen species subsequently induces cell wall loosening and expansion for bud sprouting
Project description:This study investigated changes in the transcriptome of outdoor grown leafy spurge crown buds as they progress from paradormancy in August and September into endo dormancy in October through to ecodormancy in November and December. Keywords: Dormancy leafy spurge adventitious-buds