Because of its key role in secondary phenylpropanoid metabolism, Phe ammonia-lyase is one of the most extensively studied plant enzymes. To provide a basis for detailed structure-function studies, the enzyme from parsley (Petroselinum crispum) was crystallized, and the structure was elucidated at 1.7-A resolution. It contains the unusual electrophilic 4-methylidene-imidazole-5-one group, which ...

The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-f...

Nitrate is one of the major sources of nitrogen for the growth of plants. It is taken up by plant roots and transported to the leaves where it is reduced to nitrite in the. The main objective of this research was to investigate stimulatory effects of sodium nitrate, potassium nitrate, ammonia and urea on the production/generation of the nitrate reductase mRNA in Triticum aestivum plants. The pl...

The feasibility of biogas stripping to remove ammonia in the anaerobic digestion of source segregated food waste was investigated. It was found in batch experiments that ammonia could be removed from digestate and that the removal followed 1 order kinetics with respect to total ammonia nitrogen concentration. Increasing temperature, biogas flow rate and initial pH all increased removal rates. U...

Ammonia volatilization is a major N loss process for surface-applied manures and urea fertilizers. The lost ammonia is important for both agricultural and non-agricultural ecosystems because it: i) is a direct loss of plant available N to the farmer, ii) reduces the N:P ratio in manure, which accelerates P build-up in soils, and iii) contributes to eutrophication in aquatic and low-N input ecos...

Constructed wetlands have been used effectively to reduce the mass loads of organic and nutrient components from swine anaerobic lagoons. Continuous marsh wetlands with gentle slope and intermittent flows seem to be the best for promoting oxidation and minimizing ammonia volatilization. However, the pond section of the marsh-pond-marsh section could potentially be effectively aerated by mechani...

The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Comp...

The explanation of the formation of amides in green plants is one of the oldest problems of plant biochemistry. Since the discovery in 1806 of asparagine in asparagus shoots by Vauquelin and Robiquet (1) and the demonstration in 1848 by Piria (2) of the derivation of this substance in seedlings from the proteins of the seeds and of its chemical relationship to malic acid, asparagine and its lat...

The nitrogen-fixing symbiosis between rhizobia and legume plants is a model of coevolved nutritional complementation. The plants reduce atmospheric CO(2) by photosynthesis and provide carbon compounds to symbiotically associated bacteria; the rhizobia use these compounds to reduce (fix) atmospheric N(2) to ammonia, a form of nitrogen the plants can use. A key feature of symbiotic N(2) fixation ...