model-organisms
Model organisms are select plant species studied intensively to uncover fundamental biological principles, chosen for their tractable genetics, short life cycles, and well-characterized genomes. Because core cellular and developmental pathways are conserved across the plant kingdom, discoveries made in these representative species illuminate how plants grow, respond to their environment, and regulate gene expression more broadly. This approach has accelerated plant biology research by providing shared experimental frameworks that allow findings to be translated across diverse species.
open_in_new WikipediaPubMed · 2026-04-15
Scientists discovered that a UV-light sensing system found in ancient liverworts shares a core mechanism with flowering plants like Arabidopsis, but the regulatory proteins that fine-tune the response have evolved differently over 400+ million years. This reveals how plants diversified their defenses against harmful UV-B radiation since first colonizing land.
The core UV-B photoreceptor cycle (UVR8) is functionally conserved between liverworts and flowering plants like Arabidopsis, confirming it existed in the last common ancestor of all land plants over 400 million years ago.
The regulatory protein SPA plays a much weaker role in liverworts than in Arabidopsis — liverwort spa mutants showed only a very weak developmental phenotype, unlike the strong effects seen when the equivalent gene is disrupted in Arabidopsis.
Liverwort SPA mutants showed enhanced UV-B tolerance, revealing that MpSPA acts as a negative regulator of UV-B signaling — the opposite functional emphasis compared to its Arabidopsis counterparts.
