E. L. Voigt

Publications (2)3.95 Total impact

• Article: Antioxidative enzymatic protection in leaves of two contrasting cowpea cultivars under salinity

  J. M. Maia, C. E. Costa de Macedo, E. L. Voigt, J. B. S. Freitas, J. A. G. Silveira
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  ABSTRACT: The aim of this work was to investigate the role of the antioxidant enzymes in salt tolerance comparing the salt-sensitive (Pérola) and a salt-tolerant (Pitiúba) cultivar of cowpea [Vigna unguiculata (L.) Walp.]. Salt stress (100 mM NaCl for 8 d) reduced the leaf growth rate more in the sensitive cultivar. The salt-induced decrease in the relative water content, Na+ accumulation and increase in leaf electrolyte leakage was similar in both cultivars. Salt stress induced a higher increase in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and phenol peroxidase (POX) in the tolerant cultivar than in sensitive one.
  Biologia Plantarum 02/2013; 54(1):159-163. · 1.97 Impact Factor
• Article: Involvement of cation channels and NH4+-sensitive K+ transporters in Na+ uptake by cowpea roots under salinity

  E. L. Voigt, R. F. Caitano, J. M. Maia, S. L. Ferreira-Silva, C. E. C. De Macêdo, J. A. G. Silveira
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  ABSTRACT: Na+ accumulation was investigated in the roots of 11-d-old cowpea [Vigna unguiculata (L.) Walp.] plants. The relative contribution of different membrane transporters on Na+ uptake was estimated by applying Ca2+, K+, NH4 +, and pharmacological inhibitors. Na+ accumulation into the root symplast was decreased by half in the presence of 1 mM Ca2+ and it was almost abolished by 100 mM K+. The inhibitory effect of external NH4+ on Na+ accumulation was more pronounced in the roots of NH4 +-free growing plants. Na+ accumulation was reduced about 73 % by 0.1 mM flufenamate and it was almost blocked by 2 mM quinine. In addition, 20 mM tetraethylammonium and 1.0 mM Cs+ decreased Na+ accumulation by 28 and 30 %, respectively. These results evidenced that low-affinity Na+ uptake by cowpea roots depends on Ca2+-sensitive and Ca2+-insensitive pathways. The Ca2+-sensitive pathway is probably mediated by nonselective cation channels and the Ca2+-insensitive one may involve K+ channels and to a lesser extent NH4 +-sensitive K+ transporters.
  Biologia Plantarum 04/2012; 53(4):764-768. · 1.97 Impact Factor