In Arabidopsis, egg-cell proteins SDN1–3 prevent polyspermy by degrading specific miRNAs (miR833a, miR395a/f, miR827). This turnover ensures the expression of ECS1/2 endopeptidases, which establish a polytubey block post-fertilization to maintain genomic integrity.

References:

• Shen K, Qu M, Zhou X, et al. Degradation of detrimental microRNAs safeguards the fertilized egg cells to establish an ECS-dependent polytubey block in Arabidopsis[J]. Developmental cell, 2025.