Legumes, which develop a symbiosis with nitrogen-fixing bacteria, have an increased demand for iron. Iron is required for the synthesis of iron-containing proteins in the host, including the highly abundant leghemoglobin, and in bacteroids for nitrogenase and cytochromes of the electron transport chain. Deficiencies in iron can affect initiation and development of the nodule. Within root cells,...

Actinomycetes from the genus Frankia induce nitrogen-fixing root nodules on actinorhizal plants in the "core rosid" clade of eudicots. Reported here are nine partial Frankia 16S rRNA gene sequences including the first from host plants of the rosaceous genera Cercocarpus and Chamaebatia, 24 partial glutamine synthetase (GSI; glnA) sequences from Frankia in nodules of 17 of the 23 actinorhizal ge...

Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen-fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule) where th...

A simple and reliable method for the detection of specific nitrogen-fixing bacteria in both free-living and bacteroid forms is essential for the development and application of biofertilizer. Traditionally, a polyclonal antibody generated from an immunized rabbit was used for detection. However, the disadvantages of using a polyclonal antibody include limited supply and cross-reactivity to relat...

As a warm climate species, soybean is highly sensitive to chilling temperatures. Exposure to chilling temperatures causes a significant reduction in the nitrogen fixation rate in soybean plants and subsequent yield loss. However, the molecular basis for the sensitivity of soybean to chilling is poorly understood. In this study, we identified cold-responsive miRNAs in nitrogen-fixing nodules of ...

Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean is an important leguminous crop worldwide. Soybean hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition of the root nodules. Our previous study showed that N2O reductase can be used to mitigate N2O emission from s...

The synthesis of (14)C-labeled xanthine/hypoxanthine, uric acid, allantoin, allantoic acid, and urea from [8-(14)C]guanine or [8-(14)C]hypoxanthine, but not from [8-(14)C]adenine, was demonstrated in a cell-free extract from N(2)-fixing nodules of cowpea (Walp.). The (14)C recovered in the acid/neutral fraction was present predominantly in uric acid and allantoin (88-97%), with less than 10% of...