Project description:sRNA-seq profiling of 10 time points during germination in Arabidopsis, from freshly harvested seed, through mature seed, stratification, germination and to post-germination.
Project description:Regulation of seed germination by dormancy relies on a complex network of transcriptional and post‐transcriptional modifications during seed imbibition that controls seed adaptive responses to environmental cues. High‐throughput technologies have brought significant progress in the understanding of this phenomenon and have led to identify major regulators of seed germination, mostly by studying the behaviour of highly differentially expressed genes. However, the actual models of transcriptome analysis cannot catch additive effects of small variations of gene expression in individual signalling or metabolic pathways, which are also likely to control germination. Therefore, the comprehension of the molecular mechanism regulating germination is still incomplete and to gain knowledge about this process we have developed a pathway‐based analysis of transcriptomic Arabidopsis datasets, to identify regulatory actors of seed germination. The method allowed quantifying the level of deregulation of a wide range of pathways in dormant versus non‐dormant seeds. Clustering pathway deregulation scores of germinating and dormant seed samples permitted the identification of mechanisms involved in seed germination such as RNA transport or vitamin B6 metabolism, for example. Using this method, which was validated by metabolomics analysis, we also demonstrated that Col and Cvi seeds follow different metabolic routes for completing germination, demonstrating the genetic plasticity of this process. We finally provided an extensive basis of analysed transcriptomic datasets that will allow further identification of mechanisms controlling seed germination.
Project description:RNAseq profiling of 10 time points during germination in Arabidopsis, from freshly harvested seed, through mature seed, stratification, germination and to post-germination.
Project description:Arabidopsis noncoding RNA HID1 acts as a positive regulator to promote phyB-mediated seed germination by modulating the biosynthesis of abscisic acid.
Project description:methylC-seq profiling of 4 time points during germination in Arabidopsis, from mature seed, through stratification, germination and to post-germination.
Project description:Arabidopsis noncoding RNA HID1 acts as a positive regulator to promote phyB-mediated seed germination by modulating the biosynthesis of abscisic acid.
Project description:Arabidopsis noncoding RNA HID1 acts as a positive regulator to promote phyB-mediated seed germination by modulating the biosynthesis of abscisic acid.
Project description:Production of morphologically and physiologically variable seeds is an important strategy that helps plants to survive in unpredictable natural conditions. However, the model plant Arabidopsis thaliana and most agronomically essential crops yield visually homogenous seeds. Using automated phenotype analysis, we observed that in Arabidopsis small seeds tend to have higher primary and secondary dormancy levels when compared to large ones. Transcriptomic analysis revealed distinct gene expression profiles between large and small seeds. Large seeds had higher expression of translation-related genes implicated in germination competence. In contrast, small seeds showed elevated expression of many positive regulators of dormancy, including a key regulator of this process – the DOG1 gene. Differences in DOG1 expression were associated with differential production of its alternative cleavage and polyadenylation isoforms where in small seeds proximal poly(A) site is selected resulting in a short mRNA isoform. Furthermore, single-seed RNA-seq analysis demonstrated that large seeds resemble DOG1 knockout mutant seeds. Finally, on the single seed level, the expression of genes affected by seed size was correlated with the expression of genes positioning seeds on the path towards germination. Our results demonstrate an unexpected link between seed size and dormancy phenotypes in a species producing highly homogenous seed pools, suggesting that the correlation between seed morphology and physiology is more widespread than initially assumed.
