Mechanisms of stress response in the root stem cell niche.

Abstract

As plants are sessile organisms unable to escape from environmental hazards, they need to adapt for survival. The stem cell niche in the root apical meristem is particularly sensitive to DNA damage induced by environmental stresses such as chilling, flooding, wounding, UV, and irradiation. DNA damage has been proven to cause stem cell death, with stele stem cells being the most vulnerable. Stress also induces the division of quiescent center cells. Both reactions disturb the structure and activity of the root stem cell niche temporarily; however, this preserves root meristem integrity and function in the long term. Plants have evolved many mechanisms that ensure stem cell niche maintenance, recovery, and acclimation, allowing them to survive in a changing environment. Here, we provide an overview of the cellular and molecular aspects of stress responses in the root stem cell niche.