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:Temperate perennial plants have to adapt their growth in order to survive over winter conditions and protect their tissues by entering into dormancy. The dormancy phenomenon is a complex process regulated by many factors, externals (photoperiod and temperature) or internals through the transport towards the buds. In order to better understand the molecular mechanisms involved in the regulation of dormancy, we conducted a transcriptomic analysis of flower buds from the late flowering sweet cherry cultivar 'Fertard' during dormancy, from October 2017 to March 2018.
2023-04-15 | GSE229429 | GEO
Project description:Transcriptome sequencing of sweet cherry flower buds
Project description: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.
Project description:Chromatin immunoprecipitation-sequencing (ChIP-seq) is a robust technique to study interactions between proteins, such as histones or transcription factors, and DNA. This technique in combination with RNA-sequencing (RNA-seq) is a powerful tool to better understand biological processes in eukaryotes. We developed a combined ChIP-seq and RNA-seq protocol for tree buds (Prunus avium L., Prunus persica L Batch, Malus x domestica Borkh.) that has also been successfully tested on Arabidopsis thaliana and Saccharomyces cerevisiae. Tree buds contain phenolic compounds that negatively interfere with ChIP and RNA extraction. In addition to solving this problem, our protocol is optimised to work on small amounts of material. Furthermore, one of the advantages of this protocol is that samples for ChIP-seq are cross-linked after flash freezing, making it possible to work on trees growing in the field and to perform ChIP-seq and RNA-seq on the same starting material. Focusing on dormant buds in sweet cherry, we explored the link between expression level and H3K4me3 enrichment for all genes, including a strong correlation between H3K4me3 enrichment at the DORMANCY-ASSOCIATED MADS-box 5 (PavDAM5) loci and its expression pattern. This protocol will allow analysis of chromatin and transcriptomic dynamics in tree buds, notably during its development and response to the environment.
Project description:In deciduous fruit trees, entrance into dormancy occurs in later summer/fall, concomitantly with the shortening of day length and decrease in temperature. Generally speaking, dormancy can be divided into endodormancy, ecodormancy and paradormancy. In Prunus species flower buds, entrance into the dormant stage occurs when the apical meristem is partially differentiated; during dormancy, flower verticils continue their growth and differentiation. In this work we focused our attention on flower bud development during winter in peach. In order to understand how bud development progress is regulated during winter we integrated cytological epigenetic and chromatin genome wide data with transcriptional outputs to obtained a complete picture of the main regulatory pathways involved in endodormancy.