Comparison of Atrazine Absorption by Underground Tissues of Several Plant Species

Abstract

Excised roots of corn (Zea maysL. ‘B73 × Mo 17′) and oat (Avena sativaL. ‘Goodfield’) and potato (Solanum tuberosumL. ‘Kennebec’) tuber slices absorbed14C-atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in a similar manner during short (1 to 30 min) absorption periods. Within 30 min, atrazine concentrations in tissues and ambient solution were equal. After 24 h of absorption, corn roots contained the most14C, followed in order by velvetleaf (Abutilon theophrastiMedic.) roots, oat roots, and potato tuber slices. Corn and velvetleaf accumulated14C to concentrations above the ambient solution. Efflux of14C was slower for corn than oat, potato, and velvetleaf. Metabolism of atrazine to hydroxyatrazine [2-hydroxy-4-(ethylamino)-6-(isopropylamino)-s-triazine] accounted for accumulation and slow efflux of14C in corn. These experiments show that initial, rapid absorption of atrazine is comparable, but long-term accumulation differs among these tissues.