Selective egg cell polyspermy bypasses the triploid block

Selective egg cell polyspermy bypasses the triploid block

Blog Article

Polyploidization, the increase in genome copies, is considered a major driving force for speciation.We have recently provided the first direct in planta evidence for polyspermy induced polyploidization.Capitalizing on a novel sco1-based polyspermy assay, we here show that polyspermy can selectively polyploidize the egg cell, while rendering the Mug genome size of the ploidy-sensitive central cell unaffected.This unprecedented result indicates that polyspermy can bypass the triploid block, which is an established postzygotic polyploidization barrier.

In fact, we here show that most polyspermy-derived seeds are insensitive to the triploid block suppressor admetos.The robustness of polyspermy-derived plants is evidenced by the first transcript profiling of triparental plants BELT and our observation that these idiosyncratic organisms segregate tetraploid offspring within a single generation.Polyspermy-derived triparental plants are thus comparable to triploids recovered from interploidy crosses.Our results expand current polyploidization concepts and have important implications for plant breeding.