Table 5.

Nitrate content, proline and osmolytes concentrations measured in lettuce leaves treated with water (CONTROL) and glutamic acid and grown under two water regimes (well-watered: NO STRESS and water stress and re-watering: STRESS)

Stress	Treatment	Nitrate (mg kg−1 FW)	Proline (µg g−1 FW)	Osmolytes (mOsm kg−1 g−1 FW)
No stress	CONTROL	4812.7 ± 1713.7 b	20.2 ± 2.3 b	0.100 ± 0.01 b
	GLUTAMIC ACID	4213.0 ± 988.5 b	23.5 ± 1.7 b	0.098 ± 0.00 b
Stress	CONTROL	9171.5 ± 840.9 a	438.0 ± 83.6 a	0.193 ± 0.01 a
	GLUTAMIC ACID	7139.6 ± 449.9 a	455.5 ± 132.2 a	0.190 ± 0.01 a

Measures were taken during the water stress (3/07). Values are means ± SE (n = 3). Data were subjected to two-way ANOVA. Different letters, where present, represent significant differences (P  < 0.05)