Is Reactive Oxygen Species (ROS) the underlying factor for inhibited root growth in Osspr1?

Reactive oxygen species (ROS), like hydrogen peroxide (H2O2) and superoxide anion (O2(·-)), are important plant cell signaling molecules involved in diverse physiological processes, such as programmed cell death, development, cell elongation and hormonal signaling. Recently, much attention has been paid to the role of ROS in regulating plant root development. Two ROS, superoxide and hydrogen peroxide, were shown to exhibit a typical accumulation pattern in the Arabidopsis root apex and play distinct roles in root development. The latest study showed that UPBEAT1 (UPB1), a bHLH transcription factor, modulates the ROS balance by directly regulating the expression of a set of peroxidases, therefore, regulates the root cell proliferation and differentiation. In this addendum, we proposed a possible hypothesis that OsSPR1 maintained the mitochondria function to restrict H2O2 production in root apex for normal root development.