Plant stem cells maintain genome stability by limiting protein synthesis

Stem cells are the origin of the germ line in all multicellular organisms, and their genome stability is crucial for population reproduction. How stem cells avoid transmitting incorrect genetic information to the next generation is a fundamental question in species continuity. Here, we show that, in Arabidopsis thaliana, strict control of protein synthesis in stem cells is essential for plant stem cell fate maintenance. Increasing protein synthesis in stem cells causes an overaccumulation of unfolded/misfolded proteins and impairs stem cell maintenance. We demonstrated that stem cells are hypersensitive to unfolded/misfolded proteins, whose accumulation triggers DNA breaks, resulting in genomic instability in stem cells. Our results provide a potential mechanistic link between proteome fidelity and genome stability in stem cells and demonstrate how plants safeguard genome integrity by inhibiting protein synthesis in stem cells.