Phytochrome B stabilizes the KNOX transcription factor BP/KNAT1 to promote light-initiated seed germination in Arabidopsis thaliana.

ABSTRACT: Seed germination represents a critical step in the life cycle of plants. The far-red/red light photoreceptor phytochrome B (phyB) plays a dominant role in promoting germination by modulating gibberellin (GA) and abscisic acid (ABA) metabolism, although the underlying mechanism remains poorly understood. In this study, we identified BREVIPEDICELLUS (BP)/KNAT1, a KNOX transcription factor that acts downstream of phyB and activates light-initiated seed germination in Arabidopsis thaliana. BP undergoes ubiquitination and is degraded through the 26S proteasome pathway. phyB directly interacts with BP and stabilizes BP protein by decreasing its ubiquitination in imbibed seeds. A genome-wide transcriptomic analysis revealed that BP and phyB co-regulate the expression of genes associated with ABA

SUBMITTER: Gu D 

PROVIDER: S-EPMC12785155 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature