Table II.

Actual activity of NR in tomato and cucumber roots

Data are means (μmol NO₂⁻ g⁻¹ fresh weight h⁻¹) ± se from three independent experiments.

	Time	Control		5 mm NO3−		5 mm NO3− and Tungstate
	min
Tomato	0	0.087	±0.017	0.087	±0.017	0.0105	±0.0017
	30	0.086	±0.035	0.102	±0.022	0.0082	±0.0026
	60	0.077	±0.036	0.103	±0.028	0.0061	±0.0024
	120	0.099	±0.032	0.101	±0.042	0.0063	±0.0023
Cucumber	0	0.040	±0.021	0.040	±0.022	0.0046	±0.0015
	30	0.067	±0.015	0.019	±0.014	0.0026	±0.0026
	60	0.032	±0.012	0.051	±0.013	0.0010	±0.0034
	120	0.032	±0.008	0.047	±0.012	0.0019	±0.0019