PubMed · 2026-07-04
A new review maps how a large family of plant proteins called R2R3-MYB transcription factors controls when seeds stay dormant versus when they sprout. These proteins act as molecular switches, reading hormone signals to decide whether a seed should wait or grow.
R2R3-MYB transcription factors have expanded dramatically in land plants and regulate dormancy, germination, seed size, and seed-coat pigmentation across species.
Specific members including MYB56, MYB62, MYB96, and MYB30 integrate signals from at least four hormones (ABA, GA, jasmonates, and nitric oxide) to balance dormancy and germination.
A phylogenetic analysis revealed lineage-specific gene groupings and conserved evolutionary clades within the R2R3-MYB family, tracing its origins to roughly one billion years ago in early eukaryotes.