Introduction:

A wide range of environmental factors, such as lower temperature, drought, alkalinity, salinity, nutrient deficiency and toxicity stresses are potentially harmful to plants. The role of nitrogen as an essential nutrient and structural component of amino acids, proteins, nucleic acids and other essential components for the development has been widely documented in several species because of the importance in the processes of growth and agricultural production. However, at present, there is little literature the effect of nitrogen deficiency and toxicity on osmoregulators compounds as indicators of stress in plants. So the aim of this work was to study nitrogen compounds indicators of stress (proline, glycine betaine and choline) in response to toxic doses of N and deficient in green beans developed in a culture chamber under controlled conditions.

Method:

The nitrogen was applied to the nutrient solution in the form of NH4NO3 and increasing doses: N1 = 1.5 mM, N2 = 3.0 mM, N3 = 6.0 mM, N4 = 12.0 mM, N5 = 18.0 mM and N6 = 24.0 mM of N. The parameters analyzed were biomass accumulation, the concentration of proline, glycine betaine and choline in leaves, roots, seeds and pods of green beans cv. Strike.

Results:

The application of deficient and toxic doses of N affected the production of biomass in beans, toxic doses being the most affecting this parameter. Furthermore, note that the osmoregulators proline, glycine betaine and choline accumulated only under conditions of N toxicity (N6), however, under conditions of stress caused by a lack of N (N1) accumulation of these compounds does not occur.

Discussion and Conclusion:

The stress indicators nitrogen compounds accumulate only low toxicity conditions N (N6), however under conditions of stress caused by deficiency of N accumulation of these compounds does not occur so that could be defined as only the stress bioindicators toxicity of N. Finally, the accumulation of proline, glycine betaine and choline could act as a source of N in the cell under stress, where the accumulation of these nitrogen compounds could be used as a way of storing N.

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