BrCYP71A15 Negatively Regulates Hg Stress Tolerance by Modulating Cell Wall Biosynthesis in Yeast

Abstract

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, BrCYP71A15, which was involved in Hg stress response in yeast. In Chinese cabbage, the BrCYP71A15 gene was located on chromosome A01, which was highly expressed in roots. Additionally, the expression level of BrCYP71A15 was induced by different heavy metal stresses, and the BrCYP71A15 protein exhibited a strong interaction with other proteins. Overexpression of BrCYP71A15 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 BrCYP71A15-overexpressing cells increased over time, and Hg accumulation in yeast cells was enhanced by two-fold compared with the control. Additionally, BrCYP71A15 was translocated into the nucleus under Hg stress. The expression level of cell wall biosynthesis genes was significantly influenced by Hg stress in the BrCYP71A15-overexpressing cells. These findings suggested that BrCYP71A15 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.

Comparative transcriptome and coexpression network analysis reveals key pathways and hub candidate genes associated with sunflower (Helianthus annuus L.) drought tolerance

“…These findings suggest that these genes are involved in the response of sunflowers to drought stress, which is similar to the results of many studies. CYP707A genes were upregulated under drought stress in maize, and CYP707A1 and CYP707A2 genes were highly expressed in Arabidopsis under osmotic stress and drought stress [ 96 ]. Two key enzymes involved in ABA degradation were previously reported to exhibit specific expression patterns, namely, CYP707A3 in ductal tissues and CYP707A1 in stomata [ 97 ], suggesting that the regulation of this gene family may be tissue specific.…”