Protein synthesis in trifluralin-treated corn root tips

Abstract

The effect of trifluralin (a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) on protein synthesis in corn (Zea mays) root tips was determined . 14C-leucine uptake and subsequent incorporation into protein in intact and excised root tips was measured . Root tips were treated with and without 15 pM trifluralin for 2 hr ; incorporation of 14 C-leucine was observed during a 20-min interval . Total amino acid content in the soluble pool and protein hydrolysate was reduced in the excised tissue by the herbicide . Kinetic analysis showed trifluralin had no effect on endogenous leucine pool size nor on the rate of protein synthesis in intact tissue . Uptake was unaffected; however, in excised tissue uptake increased 100% over the control . While 14C-leucine content was greater in both the soluble pool and protein in treated, excised root tips, analysis showed the apparent increase in protein synthesis was in response to increased pool size .