PHYTOCHROME-INTERACTING FACTOR 3 represses plant salt tolerance through MADS-box transcription factor AGAMOUS-LIKE 21.
It is demonstrated that PIF3 negatively regulates plant salt tolerance in Arabidopsis, and salt stress significantly enhances the interaction between PIF3 and light-activated PHYTOCHROME B (PHYB), leading to accelerated degradation of PIF3 in light, thus alleviating its negative regulation on plant salt tolerance.