Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA.

The yeast cell wall plays an important role in maintaining cell morphology, cell integrity and response to environmental stresses. Here, we report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ). Upon salt treatment, the cell wall is thickened, broken and becomes more sensitive to the cell wall-perturbing agent sodium dodecyl sulfate (SDS). Also, mRNA levels are elevated in ρ cells. Deletion of significantly decreases the sensitivity of ρ cells to SDS after salt treatment, while overexpression of results in higher sensitivity. In addition, salt stress in ρ cells induces high levels of reactive oxygen species (ROS), which further damages the cell wall, causing cells to become more sensitive towards the cell wall-perturbing agent.