Modificaciones del sistema de cultivo para optimizar el factor de multiplicación y la calidad de plantas micropropagadas de Stevia rebaudiana, Bertoni.

[EN]: Root exudation is one of the main mechanisms involved in bioremediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Exudates stimulate the proliferation of soil microorganisms active in the degradation of these organic compounds. Sunflower (Helianthus annus) is considered a feasible species for PAHs elimination from polluted soils because its seeds germinate easily and develop deep and profuse radical system in these contaminated soils. Sunflower root exudates obtained in vitro have been shown to exert a positive effect on PAHs elimination. Readily degradable compounds found in root exudates such as amino acids have been postulated to be part of a fast pool of carbon which is rapidly utilized and cycled by the microbial cells. Beside this, it is known that reduction of phosphorous and potassium in the medium enhances amino acids production by roots. In this work, sunflower root exudates have been obtained in vitro by germinating seeds in MM medium with 25 and 50% reductions of K and P (as KH2 PO4). Amino acid profile of the exudates was determined thereafter by HPLC. Our results show that the lowest KH2 PO4 concentration (25%) resulted in higher number (12) and concentration (6.29 mgL-1 ) of amino acids in the exudates, particularly histidine and arginine. Moreover, the highest amino acid content found in this exudate with 25% of monopotassium phosphate produced a higher chemotactic index in Pseudomonas putida G7, bacteria able to degrade naphthalene. In consequence, the reduction of monopotassium phosphate concentration to a quarter in the medium can enhance biological activity of PAHs degrading microorganisms in soil thus leading to a more effective bioremediation of contaminated soils.

Bibliographic Details

Main Authors:	Vilariño Rodríguez, Susana, García Fernández, José Luis, Cantos, Manuel
Format:	póster de congreso biblioteca
Published:	Sociedad Española de Cultivo In Vitro de Tejidos Vegetales 2017-09-13
Online Access:	http://hdl.handle.net/10261/163412
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