Dynamics of Actin Filaments Play an Important Role in Root Hair Growth Under Low Potassium Stress in Arabidopsis Thaliana

This study investigates the role of actin filament dynamics in root hair growth of Arabidopsis thaliana under low potassium (K+) stress. It was found that root hairs grow faster and longer under low K+ stress compared to control conditions. The actin filaments in the sub-apex of these fast-growing root hairs were longer and more parallel, correlating with increased growth rates. The actin bundling proteins Villin1 (VLN1) and Villin4 (VLN4) were differentially regulated under low K+ stress, with VLN1 being inhibited and VLN4 induced. This regulation affected the bundling rate and filament length, influencing root hair growth. Genetic analysis confirmed the involvement of VLN1 and VLN4 in root hair growth under low K+ stress, providing insights into the molecular mechanisms of actin filament dynamics in response to nutrient stress.