Abstract

OROZCO-SOTO, Marianela; GUTIERREZ-ROJAS, Mariano  and  PERALTA-PEREZ, María del Rosario. Effect of the composition of a mixture of hydrocarbons in phenotypic response and sugar accumulation by Bouteloua curtipendula Michx. Torr. Cultivated in vitro. Polibotánica [online]. 2014, n.38, pp.159-172. ISSN 1405-2768.

Bouteloua curtipendula Michx Torr. is a Mexican grass able to adapt to adverse climatic conditions. It has been reported with phytoremediation potential to clean hydrocarbons (HC) contaminated soils. In this work, B. curtipendula was tested in vitro culture conditions with 1 500 mg HC-L^-1 culture medium, and different phenanthrene (PHE), pyrene (PYR) and hexadecane (HXD) mixtures. In all cases the length and biomass production of roots and stem decreased significantly compared with control. 100% of the seeds germinated in the medium without HC, while in mixtures with higher proportion of HDX (1100 mg HC-L^-1) germinated 75% of seeds. The highest total sugars accumulation into the culture medium, after 35 days, (40 mg of total sugars accumulated into culture medium-mg^-1 of dry root, equivalent to 200 mg of total sugar-tube) was recorded in mixture with lower HXD concentration. On the other hand, there was sugar consumption in culture without HC (225.7 ± 3 mg of total sugar-tube). Our results suggest that a greater proportion of HXD increase the toxic effect to the plants. Although there are studies devoted to quantify sugars in roots exudates to our knowledge, this is the first work dealing with sugar root exudates as response mechanism of a grass to HC stress under in vitro cultures.

Keywords : grass; phytoremediation; root exudates; hydrocarbons.