Seeds: A Unique System to Study Translational Regulation

Translational regulation is an underexplored but important aspect of gene regulation. Powerful techniques like polysome profiling and Ribo-Seq have made it possible to reveal the translational status of mRNA subsets in cells. There is extensive translational regulation during seed germination. Subpopulations of mRNAs are predestined for distinct processes depending on the physiological state of the seed. Seeds accumulate mRNA during their development and have the ability to store these mRNAs over extended periods of time. On imbibition, seeds transform from a quiescent dry state (no translation) to a fully active metabolic state, and selectively translate subsets of these stored mRNA. Thus, seeds provide a unique developmentally regulated ‘on/off’ switch for translation. Additionally, there is extensive translational control during seed germination. Here we discuss new findings and hypotheses linked to mRNA fate and the role of translational regulation in seeds. Translation is an understated yet important mode of gene regulation. We propose seeds as a novel system to study developmentally and physiologically regulated translation. Seeds accumulate mRNA during their development and have the ability to store these mRNAs over extended periods of time. On imbibition, seeds transform from a quiescent dry state (no translation) to a fully active metabolic state, and selectively translate subsets of these stored mRNA. Thus, seeds provide a unique developmentally regulated ‘on/off’ switch for translation. Additionally, there is extensive translational control during seed germination. Here we discuss new findings and hypotheses linked to mRNA fate and the role of translational regulation in seeds. Translation is an understated yet important mode of gene regulation. We propose seeds as a novel system to study developmentally and physiologically regulated translation. mRNA associated with multiple ribosomes. use of a sucrose-based density gradient to separate translating mRNAs based on their association with ribosomes. In this way the translational status of mRNA subsets in cells can be revealed. involves the deep sequencing of ribosome-protected mRNA fragments to infer the precise positioning of ribosomes on the mRNA. the absorption of water by seeds. Water moves into the seed due to diffusion and capillary action. The rate of water uptake is largely determined by the permeability of the seed coat. Seed imbibition leads to an enormous increase in the seed volume and allows the embryo to restart its metabolic processes. the regulation of protein synthesis at the level of the transcript. Some of the key factors involved in this are the lifetime of the mRNA, the probability of initiation of translation, and the regulation of the rate of protein synthesis.