Project description:Ralstonia solanacerum causes bacterial wilt disease on many important host crops, including tomato and potato. R. solanacearum cells enter a host from soil or infested water through the roots, then multiply and spread in the water-transporting xylem vessels. Despite the low nutrient and oxygen content of xylem sap, R. solanacearum grows extremely well inside the host, using denitrification to respire in this hypoxic environment. R. solanacearum growth in planta also depends successful mitigation of oxidative stress produced by both the bacterium and the host. We found that proteins encoded by norA and hmpX that are predicted to interact with nitric oxide (NO) and protect against cellular damage caused by NO. Reducing NO toxicity is especially important for Rs that generates NO via denitrifying respiration in planta, and encounters NO produced by plants as a defense and signaling molecule. By analyzing transcriptomes of mutants lacking these genes, we found that iron, sulfur, and nitrogen metabolism genes were consistently upregulated in mutants missing these genes. Our transcriptomic analysis suggests R. solanacearum mutants lacking norA and hmpX suffer oxidative stress from an increase in cellular toxicity caused by NO that leads to damage of iron, sulfur, and nitrogen metabolic proteins. Our results suggest that NorA and HmpX, contribute to oxidative stress mitigation in denitrifying cultures.
2022-01-26 | GSE194210 | GEO
Project description:sulfur-sludge 16S
| PRJNA1163972 | ENA
Project description:denitrifying sludge with aeration