Nitrogen use by plants and nitrogen flows after application of standard and biomodified nitrogen fertilizers on barley

The aim of our study was to assess the efficiency of application of biomodified nitrogen fertilizers for barley, to reveal the sources of nitrogen used for biomass formation with the use of the 15N stable isotope, and to study nitrogen flows in the system of fertilizers–soil–plants–atmosphere. We demonstrated in a model experiment the ability of the plant growth-promoting bacteria Bacillus subtilis Ch-13 to move from the granules of mineral fertilizers to plant roots and to colonize them effectively. The effectiveness of biomodified nitrogen fertilizers for barley, Nur variety, was assessed in a microfield trial. After the application of biomodified nitrogen fertilizers, the accumulation of 15N in the plants increased by 2–5 %, its incorporation in the soil decreased and gaseous losses were decreased by 7 % as compared with the use of the usual forms of fertilizers. The application of biomodified nitrogen fertilizers can be used in agricultural practice as a novel technology to regulate nitrogen flows in the system of fertilizers–soil–plants–atmosphere.

15N metabolic labeling quantification workflow in Arabidopsis using Protein Prospector

Metabolic labeling using stable isotopes is widely used for the relative quantification of proteins in proteomic studies. In plants, metabolic labeling using 15N has great potential, but the associated complexity of data analysis has limited its usage. Here, we present the 15N stable-isotope labeled protein quantification workflow utilizing open-access web-based software Protein Prospector (PP). Further, we discuss several important features of 15N labeling required to make reliable and precise protein quantification. These features include ratio adjustment based on labeling efficiency, median and interquartile range for protein ratios, isotope cluster pattern matching to flag incorrect monoisotopic peak assignment, and caching of quantification results for fast retrieval.

15N Stable Isotope Labeling PSTs in Alexandrium minutum for Application of PSTs as Biomarker

The dinoflagellate Alexandrium minutum (A. minutum) which can produce paralyticshellfish toxins (PSTs) is often used as a model to study the migration, biotransformation,accumulation, and removal of PSTs. However, the mechanism is still unclear. To provide a new toolfor related studies, we tried to label PSTs metabolically with 15N stable isotope to obtain 15N-PSTsinstead of original 14N, which could be treated as biomarker on PSTs metabolism. We then culturedthe A. minutum AGY-H46 which produces toxins GTX1-4 in f/2 medium of different 15N/Pconcentrations. The 15N-PSTs’ toxicity and toxin profile were detected. Meanwhile, the 15N labelingabundance and 15N atom number of 15N-PSTs were identified. The 14N of PSTs produced by A.minutum can be successfully replaced by 15N, and the f/2 medium of standard 15N/P concentrationwas the best choice in terms of the species’ growth, PST profile, 15N labeling result and experimentcost. After many (>15) generations, the 15N abundance in PSTs extract reached 82.36%, and the 15Natom number introduced into GTX1-4 might be 4–6. This paper innovatively provided the initialevidence that 15N isotope application of labeling PSTs in A. minutum is feasible. The 15N-PSTs asbiomarker can be applied and provide further information on PSTs metabolism.

Organo - mineral fertilization of wheat: impact on growth and N - recovery using 15N - stable isotope

Investigation was carried out to follow up the effect of organo-mineral fertilizers on yield of wheat plants grown on sand soil using 15N stable isotope. Dry matter accumulation of wheat straw yielded 14.70 g/pot and grains yielded 12.72 g/pot with application of 50% As + BF. The highest values of N-uptake by straw and grains were 144.08 mg N/pot and 320.54 mg N/pot, respectively when treated with 50% As + BF. Portions of different N sources i.e. Nitrogen derived from fertilizer (% Ndff), nitrogen derived from air (% Ndfa) and fertilizer use efficiency (% FUE), gained by grains were (% 28.20), (% 19.70) and (% 34.31) as affected by addition of (50% ammonium sulphate (As) + Bio fertilizer, (25% rice straw (Rs) + 25% As + BF) and ( 25% chicken manure (CM) + 25% As + BF), respectively.