IMPORTIN β4 Facilitates CONSTANS Nuclear Accumulation and FT Activation in Arabidopsis.

IMPORTIN β4 promotes nuclear accumulation of CONSTANS, enhancing FT activation and accelerating flowering in Arabidopsis, with loss delaying flowering and reducing FT expression.

• Why it matters: Understanding how CO accumulates in the nucleus is crucial for revealing mechanisms controlling flowering time, a key factor for plant reproductive success.
• What they did: The study used interaction assays and expression analysis to show that IMPORTIN β4 interacts with CO’s CCT domain, promotes its nuclear localization, and coincides with diurnal expression peaks.
• The result: Findings suggest that IMPORTIN β4 regulates the CO-FT module through nucleocytoplasmic partitioning, providing insight into temporal control of flowering in Arabidopsis.