RSL4-centered feedback loops shape root hair morphology

Abstract

Lu-Shen Li*

Root hairs significantly expand the surface area of roots in contact with the soil, thereby promoting water and nutrient uptake. Root Hair Defective 6-Like 4 (RSL4) is a key transcription factor regulating root hair development, yet the mechanisms underlying its post-translational regulation remain incompletely understood. Recently, we demonstrated that Calcium-dependent Protein Kinases (CPKs) integrate hormonal signals to phosphorylate RSL4, thereby enhancing its transcriptional activity. This Brief Report summarizes recent evidence on how RSL4 integrates environmental and hormonal cues at multiple regulatory levels to promote root hair growth.