PubMed · 2026-07-01
Plants use a molecular gatekeeper protein to suppress flowering genes until growing conditions are right. This study shows that nitrogen availability controls that gatekeeper through TOR kinase signaling: when nitrogen is ample, TOR phosphorylates the EBS protein to keep it stable and flowering genes quiet; when nitrogen runs low, EBS degrades and plants bolt early.
TOR kinase directly phosphorylates EBS at two specific residues (S195 and S196), stabilizing the protein and keeping flowering genes including FT transcriptionally repressed.
Nitrogen deficiency reduces TOR activity, triggering EBS protein degradation and premature activation of floral transition genes.
EBS reads two opposing histone marks (H3K27me3 and H3K4me3) and can switch its binding preference to control the shift from vegetative to reproductive growth.
