RGF1 controls PLT2 protein stability through ROS-dependent regulation of a cysteine residue in root meristem development

Abstract

AbstractThe protein concentration gradients of the master regulators of the root meristem, named the PLETHORA proteins, modulate the root meristem size. Root meristem growth factor 1 (RGF1) peptide extends the PLETHORA2 (PLT2) protein gradients by altering reactive oxygen species (ROS) distributions. However, the underlying mechanism through which the ROS alterations regulate PLT2 remains unknown. Here, we demonstrate that the 212thcysteine of the PLT2 protein plays a pivotal role in modulating PLT2 stability through the ROS altered by RGF1. The substitution of the 212thcysteine of PLT2 with serine (PLT2C212S) enhanced the PLT2 protein stability upon RGF1 and resulted in robust resistance to ROS relative to the native PLT2. Accordingly, PLT2C212Smodulated expressions of certain specific root development-related genes to a greater extent than native PLT2. In summary, these findings show that the PLT2 concentration gradient formation through ROS, modulated by RGF1, is dependent on a mechanism involving the 212thcysteine of PLT2.