What is it about?
Many plants, such as mangroves, have evolved the remarkable ability to let their seeds germinate directly on the mother plant—a trait known as vivipary or cryptovivipary. This strategy allows offspring to establish rapidly in harsh environments, but how plants bypass seed dormancy without losing essential stress defenses in their leaves and roots has remained a puzzle. We show that independently evolved viviparous and cryptoviviparous plants employ a convergent "less-is-more" strategy: rather than inventing new genes, they repeatedly dismantle the downstream genetic switches responsible for seed drying and dormancy, while keeping general stress-hormone signaling intact. This work uncovers how the targeted loss of seed-specific genetic programs drives evolutionary innovation, offering valuable insights into seed biology and crop improvement.
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Why is it important?
In summary, our study resolves the evolutionary basis of (crypto)vivipary via asymmetric dismantling. We show that continuous development after the loss of seed dormancy is driven not by novel gene innovation, but by convergent removal of a specific “molecular brake” module. By retaining upstream ABA/GA signaling needed for vegetative stress tolerance while selectively purging dry-seed–specific downstream effectors, (crypto)vivipary achieves both rapid offspring establishment and high adult stress tolerance. This functionally convergent loss of desiccation and dormancy machinery identifies the genetic basis of (crypto)vivipary as a natural analogue of pre-harvest sprouting. The model thus provides a validated blueprint for breeding climate-resilient crops by emulating naturally selected gene loss to reduce the risk of undesirable pleiotropy.
Perspectives
This study has several limitations. Our analyses did not resolve functional implications of subtle vivipary and cryptovivipary differences, and the roles of lineage-specific contracted genes remain are yet to be tested. Future work should prioritize the functional characterization of these genes and implement field experiments to assess ecological performance. Consistent with prior mangrove research on convergent sequence changes in seed-development genes, our findings advance the understanding of convergent evolution by revealing that repeated evolution of vivipary and cryptovivipary can be achieved through structured loss of downstream seed-effectors. These genetic targets provide a foundation for future experimental analyses in mangroves, potentially through CRISPR-based approaches that are now feasible given recent transformation and gene-editing protocols for Kandelia obovata. Beyond mechanistic insight, this framework could support conservation and restoration efforts as climate change continues to threaten intertidal habitats.
Dr. Kanglu Zhao
Zhejiang A and F University
Read the Original
This page is a summary of: Convergent innovation of (crypto)vivipary via asymmetric dismantling of seed desiccation and dormancy machinery, Proceedings of the National Academy of Sciences, October 2026, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2602105123.
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