Figure 4.

Effect of a sublethal dose of the phosphonate herbicide glyphosate on AAAs and DAHP synthase activity levels in Nicotiana plumbaginifolia cultured cells. (a) The intracellular free AAA pools were quantified at increasing times after the addition of 0.5 mM glyphosate to the culture medium 6 days after subculturing and compared with those in untreated controls. (b) DAHP synthase activity was measured in extracts prepared from the same samples. In all cases, data are the means ± SE of three independent biological replicates. The asterisk represents a value in treated samples that is significantly different from that in untreated controls (p < 0.01), as determined using a multiple t-test corrected for multiple comparisons using the Holm–Sidak method.