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 temporally; however, this preserves root meristem integrity and functioning 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 give an overview of the cellular and molecular aspects of stress responses in the root stem cell niche.

Fumonisin B1 as a Tool to Explore Sphingolipid Roles in Arabidopsis Primary Root Development

“…Upon short-term treatment with FB1, WOX5 expression was strongly repressed ( Figure 4 D). Under normal conditions, a low QC proliferation rate maintains the root structure and meristem function [ 10 , 44 , 50 ]. Longer FB1 treatment induced cell division in the QC ( Figure 5 ).…”

“…As sessile organisms that are unable to escape from environmental hazards, plants utilize multiple pathways to cope with environmental stresses that can negatively affect DNA replication or cause DNA damage [ 10 , 11 , 51 , 52 , 53 , 54 ]. With its particular sensitivity to DNA damage induced by environmental stresses, the SCN has been shown to undergo cell death, thus protecting the genomic integrity and RAM activity to survive from severe stress [ 9 ].…”

“…Propidium iodide (PI) staining was performed as previously described [ 10 ]. For confocal microscopy, fluorescence in roots was detected using a Zeiss LSM980 laser scanning microscope (ZEISS, Oberkochen, Germany).…”

“…Auxin efflux facilitators PIN-FORMED (PIN) family proteins generate and stabilize the auxin maximum and gradient, thus guiding root growth [ 8 ]. Being of a sessile nature, plants are continuously exposed to various environmental stress factors that can affect DNA replication or cause DNA damage [ 9 , 10 , 11 , 12 ]. Left unrepaired, DNA damage in actively dividing cells disrupts normal cellular functions and may thus severely affect plant growth and development [ 11 , 13 , 14 , 15 ].…”

PHYTOCHROME A controls the DNA damage response and cell death tolerance within the Arabidopsis root meristem

“…Undifferentiated cells located inner within the root tip, known as the stem cell niche (SCN), control root organogenesis and indeterminate growth. Because of their constant mitotic activity, the SCN and daughter cells are highly susceptible to environmental hazards that cause DNA damage, which can activate programmed cell death (PCD) and thus avoids the transmission of mutations to dividing cells (Ubogoeva et al, 2021).…”