Seeds in the starting blocks
Farmers and researchers prime seeds to get an even germination. Now researchers from the Netherlands show in New Phytologist that priming puts the available mRNA in the translation starting blocks.
Through the priming of seeds can farmers make sure that the seeds germinate quicker and more or less at the same time. It has one disadvantage; the seeds shelve life is reduced. But what happens exactly during the priming of seeds? The researchers decided to find out.
To get enlighten what happens inside the seeds, the researchers studied two processes. Firstly, they analysed how much mRNA was coupled to the ribosomes, who translate the RNA into proteins. Primed seeds have more ribosome coupled mRNA than none primed seeds. As if the mRNA is standing in the starting blocks for protein translation.
At the end of the priming process, the translation of mRNA into proteins is paused
As second the researchers studied which mRNAs the ribosomes translate. In this way the researchers could see for the different priming stages which genes the seeds were translating in more or in less proteins. Two stages were standing out.
At the time the seeds were in the middle of the priming process the seeds turned out to translate more genes. While at the end of the priming process, more genes were translated less. This where mostly those genes involved in the translation process.
The researchers also checked if they could find genes needed for the priming process. They identified 30 candidate genes. Between those, one stood out, RGGB. RGGB has a sibling, RGGC, who is influencing the germination of seeds. Is RGGC absent, then seeds germinate quicker. However, RGGB appears to have the opposite effect. In absence of RGGB seeds are germinating slower.
Primed seeds are standing in the starting block ready to germinate
RGGB appears to have less effect on the priming process self. Although seeds without RGGB germinate slower, they still could be primed.
Priming appears to put the in the seeds available mRNA in the protein translation starting blocks. At the same time, it creates a kind of pause in the translation process through slowing down the translation of genes required.
Literature
Gran, P., Visscher, T.W., Bai, B., Nijveen, H., Mahboubi, A., Bakermans, L.L., Willems, L.A.J. and Bentsink, L. (2025), Unravelling the dynamics of seed-stored mRNAs during seed priming. New Phytol. https://doi.org/10.1111/nph.70098
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