Seed Developmental Mechanisms in Arabidopsis

Seed formation in Arabidopsis thaliana begins with the fertilisation of the egg and central cell, giving rise to the embryo and endosperm, respectively, both enveloped by the maternally derived seed coat. Precise coordination between these tissues, orchestrated by hormonal cues such as auxin and brassinosteroids, epigenetic regulators, transcriptional networks and mechanical feedback, ensures proper cellular proliferation, differentiation and maturation. Early endosperm development features a syncytial phase regulated by cell-cycle genes and cytokinin signalling, while subsequent cellularisation synchronises with seed coat expansion. Inter-compartmental signalling pathways mediated by proteases, receptor kinases and small RNAs reinforce tissue integrity, for example by regulating embryonic cuticle formation or paternal effects on endosperm division. Mechanical forces arising from embryo and endosperm growth feed back to modulate cell wall remodelling and hormone accumulation in the seed coat. Recent advances in transcriptomics and imaging have deepened our understanding of gene regulatory networks and biophysical determinants underlying seed size, nutrient allocation and species-specific barriers, with implications for crop improvement, hybridisation strategies and the evolutionary success of spermatophytes.

Research from Nature Portfolio

Recent studies have revealed that the maternal seed coat communicates with the endosperm via brassinosteroid signalling, with seed-coat-derived brassinosteroids tuning endosperm proliferation independently of its cellularisation timing. Investigations into fertilisation-induced auxin synthesis have identified MADS-box regulators, notably AGL62, as key drivers of auxin biosynthesis in the endosperm, which in turn triggers seed coat and fruit development. Foundational work has further demonstrated a paternal effect mediated by miR159, where sperm-transmitted microRNA represses maternal MYB targets to initiate endosperm nuclear division, uncovering a novel layer of parental interplay in early seed formation.

Seed Developmental Mechanisms in Arabidopsis publication trend

The graph below shows the total number of articles in seed developmental mechanisms in arabidopsis across all publications each year (not limited to Nature Index journals).

Technical terms

Endosperm: A nutritive tissue formed by fertilisation of the central cell, supporting embryo growth.

Integuments (Seed coat): Maternal tissues surrounding the embryo and endosperm that form the protective seed coat.

Auxin: A class of phytohormones essential for organ patterning, cell division and seed coat development.

Brassinosteroids: Steroid phytohormones that regulate cell wall remodelling and coordinate seed coat–endosperm communication.

MicroRNA (miRNA): Small non-coding RNAs that post-transcriptionally regulate gene expression, including parental contributions to endosperm division.

MADS-box transcription factors: A family of DNA-binding proteins that control developmental programmes such as endosperm growth and auxin biosynthesis.

Mechanosensitive cell layer: A specialised seed-coat layer that perceives mechanical stress from internal tissues to modulate hormone accumulation and cell wall dynamics.

References

1. Seed coat-derived brassinosteroid signaling regulates endosperm development. Nature Communications (2024).
2. Molecular basis and evolutionary drivers of endosperm-based hybridization barriers. Plant Physiology (2024).
3. A mechanically sensitive cell layer regulates the physical properties of the Arabidopsis seed coat. Nature Communications (2015).
4. Transcriptome Analysis of Proliferating Arabidopsis Endosperm Reveals Biological Implications for the Control of Syncytial Division, Cytokinin Signaling, and Gene Expression Regulation. Plant Physiology (2008).
5. Mechanism of fertilization-induced auxin synthesis in the endosperm for seed and fruit development. Nature Communications (2022).
6. A stress-response-related inter-compartmental signalling pathway regulates embryonic cuticle integrity in Arabidopsis. PLOS Genetics (2019).
7. Clearance of maternal barriers by paternal miR159 to initiate endosperm nuclear division in Arabidopsis. Nature Communications (2018).