Abstract
Cryptovivipary and vivipary, referred to as (crypto)vivipary, occur across multiple angiosperm lineages and enable embryos to continue developing before dispersal. Yet, this trait raises a fundamental question: how are seed-specific abscisic acid (ABA) responses modulated to support continuous embryonic growth without compromising ABA-dependent vegetative stress tolerance? Here, integrating phylogenomic analyses of independently evolved (crypto)viviparous lineages with spatiotemporal transcriptomics and functional validation, we show that (crypto)vivipary evolved via a convergent “less-is-more” strategy rather than through novel genes or single master loci (e.g.,
DOG1
). While upstream hormonal cores (e.g., ABA/GA signaling) are largely conserved, downstream seed desiccation and dormancy effectors are asymmetrically dismantled across cryptoviviparous and viviparous lineages. This remodeling, encompassing 38 shared contracted orthogroups and hundreds of lineage-specific losses, converges on eliminating the execution machinery for seed desiccation tolerance and dormancy maintenance. Consistently, orthologs of the contracted genes are enriched for dry-seed–specific expression and ABA responsiveness in non-(crypto)viviparous species. Furthermore, disrupting representative
Arabidopsis
orthologs (e.g.,
SESA1
,
TIP3.2
,
LEA25
,
ECP63
) recapitulates (crypto)viviparous-like phenotypes, including precocious germination, elevated seed moisture, and in most mutants, compromised storage longevity. Together, our findings demonstrate how structured contraction of terminal seed-specific modules uncouples seed developmental fate from systemic stress signaling, illuminating the molecular architecture of (crypto)vivipary.