Adaptive seed-size variation in Arabidopsis thaliana

Abstract

While genetic adaptation to local environments in plants is well established, the underlying mechanisms involved are not fully understood. We focus on seed size and seedling survival, fundamental life-history traits that are also critical for agriculture. Using the model plant Arabidopsis thaliana, we investigate the adaptive role of seed size and its genetic and ecological underpinnings. Seed size in A. thaliana is highly variable, has a strong genetic basis, and exhibits geographic patterns consistent with local adaptation. Notably, beach samples from southern Sweden consistently produce significantly larger seeds compared to inland samples, a pattern we confirm through extensive sampling of multiple beach and inland populations.

We show that large-seeded plants exhibit higher fitness, particularly during seedling establishment, which provides robust evidence for the adaptive advantage of this trait in beach environments. Additionally, we explore the trade-off between seed size and seed set, as well as the physiological differences between large and small seeds. Our findings highlight the ecological and evolutionary significance of seed size variation and its role in local adaptation.

References

36-yearstudy reveals stability of a wild wheat population across microhabitats (link is external)

Life-historytrade-offs explain local adaptation in Arabidopsis thaliana (link is external)

Efficient in planta gene targeting in tomatousing geminiviral replicons and the CRISPR/Cas9 system (link is external)