We have proposed that reactive oxygen species (ROS) play essential roles in cell differentiation. Enzymes belonging to the NADPH oxidase (NOX) family produce superoxide in a regulated manner. We have identified three distinct NOX subfamilies in the fungal kingdom and have shown that NoxA is required for sexual cell differentiation in Aspergillus nidulans. Here we show that Neurospora crassa NOX-1 elimination results in complete female sterility, decreased asexual development, and reduction of hyphal growth. The lack of NOX-2 did not affect any of these processes but led instead to the production of sexual spores that failed to germinate, even in the presence of exogenous oxidants. The elimination of NOR-1, an ortholog of the mammalian Nox2 regulatory subunit gp67phox, also caused female sterility, the production of unviable sexual spores, and a decrease in asexual development and hyphal growth. These results indicate that NOR-1 is required for NOX-1 and NOX-2 functions at different developmental stages and establish a link between NOX-generated ROS and the regulation of growth. Indeed, NOX-1 was required for the increased asexual sporulation previously observed in mutants without catalase CAT-3. We also analyzed the function of the penta-EF calcium-binding domain protein PEF-1 in N. crassa. Deletion of pef-1 resulted in increased conidiation but, in contrast to what occurs in Dictyostelium discoideum, the mutation of this peflin did not suppress the phenotypes caused by the lack of NOX-1. Our results support the role of ROS as critical cell differentiation signals and highlight a novel role for ROS in regulation of fungal growth.
- American Society for Microbiology
- Nadph oxidases nox-1 and nox-2 require the regulatory subunit ...
The Chemical Aspect of NOx Scrubbing
With the passage of the 1990 Clean Air Act Amendments, many chemical and metal industries and utility producers will now be required to further limit the amount of NOx (Nitrogen Oxides) produced. NOx is a precursor to ozone in the atmosphere, and is believed to be a major contributor to acidic deposition (acid rain). Formation of ozone:NOx is produced in a variety of different processes, including combustion equipment, gas turbines, incinerators, kilns and power plants. NOx also is emitted as by product from...
Advanced SNCR - NOx Reduction on Large Utility Boilers
Fuel Tech has recently completed full-scale demonstrations of Advanced Selective NonCatalytic Reduction systems on a number of large utility boilers (>600MW) firing a variety of fuel types. The systems use the latest flexible injection technology and are controlled with a balanced algorithm utilizing unit load, a full grid of continuous furnace temperatures and the plant continuous emissions monitoring system (CEMS). Fuel Tech has more installed SNCR applications than any other technology supplier, with more...
NOx Scrubbing Technology Breakthrough
Pacific Rim Design and Development and Dupont are proud to introduce a technology breakthrough in the treatment and safe elimination of problematic nitric oxide (NO) and nitrogen dioxide (NO2 ). There are six forms of nitrogen oxide (NOx); the drawings to the right show the two most problematic forms. These two are of particular interest because they are identified as atmospheric pollutants (greenhouse gases) and subject to regulatory control by the Environmental Protection Agency (EPA) and many other organizations...
Layered Reduction Technologies for Effective NOx Control
The control of nitrogen oxides (NOx) is a well-known requirement for utility and industrial furnaces alike. Although the regulations and corresponding emission limits vary greatly, the need for substantial reduction is becoming universal. There are a few existing NOx reduction technologies which have been proven effective in a variety of applications. The most appropriate solution for NOx reduction on any furnace application is to intelligently apply each of the proven technologies in a layered system.
Exhaust Gas Treatments for NOx Reduction to Add to Global Warming
The enforcement of year 2007 stringent emission norm for reduced NOx reduction/oxides of nitrogen gases from the diesel exhaust and the after treatment to reduce them will add to global warming by several fold according to renowned engine combustion kinetics, emission control process expert and inventor -Mr.Srinivasan Gopalakrishnan, Hydrodrive Systems & Controls Pvt. Ltd, India. His invention of the PROCESS AND SYNTHESIZER FOR MOLECULAR ENGINEERING OF MATERIALS had been granted the Great Britain Patent and...