Project description:We analyzed the monsome and polysome associated transcripts of seeds and seedlings and identify transcripts specifically associated with monosome and polysome in both tissues The aim was to generate a global view about the state of mRNA storage in the seeds and the their fate during seed germination.
Project description:Wild type and alkbh1a/1b seeds were stratified for two days, dry and stratified seeds were collected to extract total RNA for mRNA-seq. We then performed gene expression profiling analysis using data obtained from mRNA-seq.
Project description:Functionally complemented dog1-1 mutant with a YFP-DOG1 fusion protein under the control of its native promoter were used as starting material for in vivo pull-down of YFP: DOG1 and its interacting proteins from seed tissues in native conditions. DOG1 interacting proteins were identified by mass spectrometry. Pull-downs were performed in biological triplicates using dry or 24 h water imbibed seeds, directly after harvest (dormant condition) and after 7 months of dry storage (non-dormant condition).
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.
Project description:Seeds establish dormancy for survival under severe conditions and break it for renascence under suitable ones. Here We identify a fate switch constituted by MKK3-MPK7 and ERF4 responsible for the transition of seeds state from dormancy to germination. We show that the MKK3-MPK7 module is activated by dormancy-breaking factors, affects and relies on the expression of some EXPAs to control seed dormancy. Furthermore, we identify a direct downstream substrate of this module, ERF4, which can suppress the expression of these EXPAs by directly binding to the GCC box in their exon region. The activated MKK3-MPK7 module phosphorylates ERF4 and leads to its rapid degradation, thereby releasing its inhibitory effect on the expression of these EXPAs. Our work identifies a signaling chain integrated by protein phosphorylation, degradation, and gene transcription, dependent on which the germination promoters within the embryonic nucleus are sensing and activated by the germination signals from the ambient conditions.