Project description:Background: It has been observed in some plant-virus interaction under certain circumstances that the plants show a sign of healing from virus-infection, a phenomenon called symptom recovery. The nature of molecular processes behind symptom recovery has been an enigma in plant virology for a long time. Discovery of RNA silencing provided a possible mechanism to explain some aspects of recovery but not all. Results: We provide evidence that silencing is not the reason for recovery in CymRSV-infected Nicotiana benthamiana plants. Transcriptome analysis followed by in situ hybridization experiments shed light on the expressional changes in the shoot apical meristem (SAM) region upon virus infection. We observed a severe loss of meristem function in the SAM which was accompanied by the downregulation of meristem-specific genes. Among the upregulated genes we found an enrichment of salicylate-metabolism and signalling, and autophagy-related functions (among many others) suggesting that these genes might play a role in shoot necrosis and symptom recovery. Conclusion: Our data suggest that the loss of meristem function is a result of salicylate-induced programmed cell death.
Project description:gnp07_regeneome_transdifferenciation - microdissection - Study of the moleculars mecanism during transdifferenciation of Root ApicalMeristem to Shoot Apical Meristem - middle of growth permits to induce transdifferenciation of root apical meristem to shoot apical meristem
Project description:gnp07_regeneome_transdifferenciation - microdissection - Study of the moleculars mecanism during transdifferenciation of Root ApicalMeristem to Shoot Apical Meristem - middle of growth permits to induce transdifferenciation of root apical meristem to shoot apical meristem 6 dye-swap - time course
Project description:au10-15_cineroots - transdifferentiation - Study of the molecular mechanism during transdifferenciation from root apical meristem to shoot apical meristem - culture in middle with different hormons, permits transdifferenciation from root to shoot tissues.
Project description:au10-15_cineroots - transdifferentiation - Study of the molecular mechanism during transdifferenciation from root apical meristem to shoot apical meristem - culture in middle with different hormons, permits transdifferenciation from root to shoot tissues. 6 dye-swap - time course
Project description:We investigated the chromatin modifications H3K4me3 and H3K27me3 in the A. thaliana shoot apical meristem using INTACT reporter lines. Samples were collected in two biological replications.
Project description:DNA methylation is an epigenetic modification that specifies the basic state of pluripotent stem cells and regulates the developmental transition from stem cells to various cell types. In flowering plants, the shoot apical meristem (SAM) contains a pluripotent stem cell population which generates the aerial part of plants including the germ cells. Under appropriate conditions, the SAM undergoes a developmental transition from a leaf-forming vegetative SAM to an inflorescence- and flower-forming reproductive SAM. While SAM characteristics are largely altered in this transition, the complete picture of DNA methylation remains elusive. Here, by analyzing whole-genome DNA methylation of isolated rice SAMs in the vegetative and reproductive stages, we found that methylation at CHH sites is kept high, particularly at transposable elements (TEs), in the vegetative SAM relative to the differentiated leaf, and increases in the reproductive SAM via the RNA-dependent DNA methylation pathway. We also found that half of the TEs that were highly methylated in gametes had already undergone CHH hypermethylation in the SAM. Our results indicate that changes in DNA methylation begin in the SAM long before germ cell differentiation to protect the genome from harmful TEs.
Project description:Knowledge about an organism’s cell and tissue-specific transcriptional repertoire is essential for understanding the gene regulatory circuits that control key developmental events. The shoot apical meristem (SAM) is responsible for development of all the above ground parts of plants. Our understanding of SAM at the molecular level is far from complete. The present work investigates the global gene expression repertoire of SAMs in the garden pea (Pisum sativum). To this end, 10,346 EST sequences representing 7611 unique genes were generated from pea SAM cDNA libraries. These sequences, together with previously reported ESTs, were used to construct a 12K oligonucleotide array used to identify genes exhibiting differential SAM expression, as compared to the axillary meristem, root apical meristem, and non-meristematic tissues. We identified a number of genes that are predominantly expressed in specific cell layers or domains of the SAM, and thus are likely components of the gene networks involved in stem cell maintenance and initiation of lateral organ primordial cells. In situ hybridization confirmed the spatial localisation of some of these key genes within the SAM. Our data also indicate the diversification of some gene expression patterns and functions in legume crop plants.
Project description:All above ground organs of higher plants are ultimately derived from shoot apical meristems (SAMs). The SAM exhibits distinctive structural organization, and monocot SAMs such as maize are comprised of two cell layers, a single cell layered tunica (L1) and a corpus (L2). Although recent research has revealed roles of these cell layers in the SAM, intra- and inter-cell-layer signaling networks involved in organ development remain largely unknown except for a few differentially expressed genes. Here, we used Illumnia technology to conduct RNA-seq of L1 and L2 cell layers in maize B73 maize shoot apical meristem.