PHYTOCHROME-INTERACTING FACTORs trigger environmentally responsive chromatin dynamics in plants

Area of Science:

• Plant biology
• Molecular biology
• Epigenetics

Background:

• Light receptors and PHYTOCHROME-INTERACTING FACTORs (PIFs) integrate environmental signals into plant transcriptional networks.
• Histone variant H2A.Z occupancy and histone H3 acetylation are known regulators of environmentally responsive genes.
• The precise interface between PIF activity and these epigenomic features remains largely uncharacterized.

Purpose of the Study:

• To investigate how PIFs influence chromatin dynamics and epigenomic landscapes in response to light.
• To elucidate the molecular mechanisms by which PIFs interact with chromatin remodeling complexes.
• To understand the role of PIF-mediated epigenomic changes in plant environmental responses.

Main Methods:

• Utilized light-mediated manipulation to control PIF7 subnuclear localization and phosphorylation.
• Assayed PIF7 DNA-binding properties and its genome-wide impact on chromatin dynamics.
• Investigated direct interactions between PIFs and chromatin remodeling factors using molecular assays.

Main Results:

• PIFs rapidly reshape the H2A.Z and H3K9ac epigenetic landscape upon changes in light quality.
• PIFs directly interact with EIN6 ENHANCER (EEN), an Arabidopsis thaliana homolog of INO80 Subunit 6 (Ies6).
• This interaction facilitates PIF-mediated removal of H2A.Z.

Conclusions:

• A PIF-INO80 regulatory module is identified as a key intermediate in plant environmental response.
• This module enables plants to rapidly adjust their growth trajectories in response to environmental cues.
• The findings reveal a novel mechanism linking light perception, PIF activity, and epigenomic regulation in plants.