The mRNA-binding proteome of a critical phase transition during Arabidopsis seed germination.

Nikita Sajeev,Rémy Merret,Leónie Bentsink,Leo A. J. Willems,Antoine H. P. America,Anirban Baral

doi:10.1111/nph.17800

Nikita Sajeev, Rémy Merret + Show 4 more

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https://doi.org/10.1111/nph.17800

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Abstract

Summary Arabidopsis thaliana seed germination is marked by extensive translational control at two critical phase transitions. The first transition refers to the start of hydration, the hydration translational shift. The second shift, the germination translational shift (GTS) is the phase between testa rupture and radicle protrusion at which the seed makes the all or nothing decision to germinate.The mechanism behind the translational regulation at these phase transitions is unknown. RNA binding proteins (RBPs) are versatile players in the post‐transcriptional control of messenger RNAs (mRNAs) and as such candidates for regulating translation during seed germination.Here, we report the mRNA binding protein repertoire of seeds during the GTS. Thirty seed specific RBPs and 22 dynamic RBPs were identified during the GTS, like the putative RBP Vacuolar ATPase subunit A and RBP HSP101. Several stress granule markers were identified in this study, which suggests that seeds are prepared to quickly adapt the translation of specific mRNAs in response to changes in environmental conditions during the GTS.Taken together this study provides a detailed insight into the world of RBPs during seed germination and their possible regulatory role during this developmentally regulated process.

Highlights

Seed germination is a complex process in which the seeds need to undergo developmental transitions to successfully establish themselves as a plant
A recent study reported that certain stored messenger RNAs (mRNAs) in the dry seed are associated with single ribosomes and RNA binding proteins (RBPs) which are later translationally upregulated during germination (Bai et al, 2020)
This study provides a valuable resource for future RBP research in seeds and will be the starting point of identifying their possible regulatory role in translation during seed germination

Summary

Introduction

Seed germination is a complex process in which the seeds need to undergo developmental transitions to successfully establish themselves as a plant. At the GTS, distinct subsets of messenger RNAs (mRNAs) show differential translation which suggests dynamic regulation of germination (Bai et al, 2017). A recent study reported that certain stored mRNAs in the dry seed are associated with single ribosomes and RBPs which are later translationally upregulated during germination (Bai et al, 2020). This led to the hypothesis that certain RBPs could play a role in determining the fate of the regulated mRNAs during seed germination

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