This paper discribed plant programmed cell death(PCD),generally occuring during many developmental processes and abiotic stress conditions,is a driving cell death process regulated and controlled by gene.Reactive oxygen species(ROS) play an important signaling role in plants controlling processes such as growth,development,response to biotic and abiotic environmental stimuli,and programmed cell death.This paper reviewed the functions of ROS in plants via its production,their function in defencing environmen...