Loading...
Please wait, while we are loading the content...
Similar Documents
The Contribution of Alternative Nitrogenases to Nitrogen Fixation in Switchgrass Rhizospheres on Marginal Lands
| Content Provider | Semantic Scholar |
|---|---|
| Author | Norman, J. |
| Copyright Year | 2017 |
| Abstract | text (specific to this investigation): The productivity of switchgrass, a common biofuel crop, is limited by nitrogen (N) availability in marginal land cropping systems. Free-living diazotrophs, naturally-occurring microorganisms capable of biological N fixation, have the potential to increase switchgrass productivity without fertilizer N inputs by increasing reactive N availability in rhizosphere soils. Classical nitrogenase enzymes require Molybdenum (Mo) to function; this element could therefore limit observed rates of soil biological N fixation in Mo-depleted soils. However, alternative nitrogenase enzymes which operate without Mo, can be expressed by some freeliving diazotrophs as well. In this study we investigated the role that alternative nitrogenases play in biological N fixation in the rhizosphere of switchgrass grown without fertilizer N inputs in marginal land cropping systems. Recent work by Bellenger et al. (2014) has shown that the activity of alternative nitrogenase enzymes can be investigated by measuring the ratio between observed rates of acetylene reduction and N2 incorporation, two commonly-used assays for nitrogenase activity in soil. We measured both N2 incorporation and acetylene reduction in soils collected from switchgrass rhizospheres in three marginal land sites in Michigan, which were established as part of the Great Lakes Bioenergy Research Center Marginal Land Experiment. We found evidence for substantial alternative nitrogenase activity in soils collected from a single site (Lux Arbor), but not in soils from other sites tested. Ongoing research is investigating the edaphic factors that favor biological N fixation by alternative nitrogenases in the switchgrass rhizosphere. Furthermore, we are investigating the abundance of free-living diazotrophs and the genetic capacity of these organisms to express alternative nitrogenase enzymes across sites using quantitative PCR. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://genomicscience.energy.gov/pubs/2017abstracts/abstractpdfs/195_Evans_Sarah_Norman.pdf |
| Alternate Webpage(s) | https://genomicsgtl.energy.gov/pubs/2017abstracts/abstractpdfs/195_Evans_Sarah_Norman.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
