Co-application of selenite and phosphate reduces arsenite uptake in hydroponically grown rice seedlings: toxicity and defence mechanism

Ecotoxicol Environ Saf. 2013 May;91:171-9. doi: 10.1016/j.ecoenv.2013.01.027. Epub 2013 Feb 27.

Abstract

The study empirically evaluates the abatement of As(III) uptake in rice seedlings (7d), in presence of Se and phosphate (P) under hydroponic condition. Positive correlation between As(III) translocation to the shoots of As(III) and P treated seedlings, shows P dependent As(III) translocation in rice. Whereas, presence of both P (5 and 10μgml(-1)) and (0.75μgml(-1)) of Se significantly reduces the As(III) uptake in rice seedlings. Application of Se alone also reduces As(III) uptake both in shoots and roots significantly, however, the seedlings suffers from lipid peroxidation. Among all the studied treatments, lower rates of P (5μgml(-1)) and Se (0.75μgml(-1)) when co-applied, significantly reduced As(III) translocation to the shoots without inflicting much toxicity in the seedlings which is manifested as significant increase in biomass with lower thio-barbituric reactive substances (TBARS). Also, significantly lower TBARS in seedlings receiving As(4)+Se(0.75) and higher TBARS in As(4)+Se(1.5), demonstrates that Se applied at lower rates (0.75μgml(-1)), lowers As induced toxicity. Higher SOD, APX and guaiacol peroxidase (POD) activities in As(4)+P(5)+Se(0.75) compared to that of As(4)+P(5) and As(4)+Se(0.75), supports that lower rate of P and Se provides tolerance towards As induced stress. The nitrogen metabolism in As(4)+P+Se treated seedlings is affected adversely at higher rates of Se and P application. Overall study concluded that application of lower rates of P (5μgml(-1)) and Se (0.75μgml(-1)) provides maximum amelioration of As(III) toxicity in rice seedlings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenites / metabolism*
  • Arsenites / toxicity
  • Enzyme Activation / drug effects
  • Enzymes / metabolism
  • Hydroponics
  • Lipid Peroxidation / drug effects
  • Oryza / drug effects*
  • Oryza / metabolism
  • Phosphates / pharmacology*
  • Plant Roots / drug effects
  • Plant Roots / metabolism
  • Seedlings / drug effects*
  • Seedlings / metabolism
  • Sodium Selenite / metabolism
  • Sodium Selenite / pharmacology*
  • Water Pollutants, Chemical / metabolism*
  • Water Pollutants, Chemical / toxicity

Substances

  • Arsenites
  • Enzymes
  • Phosphates
  • Water Pollutants, Chemical
  • Sodium Selenite
  • arsenite