Negatively Regulates Hg Stress Tolerance by Modulating Cell Wall Biosynthesis in Yeast.

Over the past two decades, heavy metal pollution has been a common problem worldwide, greatly threatening crop production. As one of the metal pollutants, Mercury (Hg) causes damage to plant cells and reduces cellular and biochemical activities. In this study, we identified a novel cytochrome P450 family gene, , which was involved in Hg stress response in yeast. In Chinese cabbage, the gene was located on chromosome A01, which was highly expressed in roots. Additionally, the expression level of was induced by different heavy metal stresses, and the protein exhibited a strong interaction with other proteins. Overexpression of in yeast cells showed no response to a number of heavy metal stresses (Cu, Al, Co, Cd) in yeast but showed high sensitivity to Hg stress; the cells grew slower than those carrying the empty vector (EV). Moreover, upon Hg stress, the growth of the -overexpressing cells increased over time, and Hg accumulation in yeast cells was enhanced by two-fold compared with the control. Additionally, was translocated into the nucleus under Hg stress. The expression level of cell wall biosynthesis genes was significantly influenced by Hg stress in the -overexpressing cells. These findings suggested that might participate in HG stress tolerance. Our results provide a fundamental basis for further genome editing research and a novel approach to decrease Hg accumulation in vegetable crops and reduce environmental risks to human health through the food chain.