Table II.

Influence of H₂S exposure on the rates of photosynthesis and transpiration of wild-type and transgenic poplar and H₂S uptake rates during the photoperiod

	Wild Type	Wild Type	Transgenic	Transgenic
	0 μL L−1 H2S	0.25 μL L−1 H2S	0 μL L−1 H2S	0.25 μL L−1 H2S
Photosynthesis [μmol CO2 g fresh wt−1 h−1]	137  ± 21a	146  ± 21a	126  ± 15a	141  ± 14a
Transpiration [mmol H2O g fresh wt−1 h−1]	37.7  ± 5.9a,b	40.3  ± 4.5a	36.5  ± 3.1a,b	34.6  ± 5.1b
H2S uptake [nmol H2S g fresh wt−1 h−1]	–	223  ± 26a	–	210  ± 20a

Plants were exposed to H₂S for 48 h. The temperature during the measurements was 20°C ± 1°C and the photon flux density was 380 ± 20 μmol m⁻² s⁻¹ (within the 400–700 nm range). The data shown are means ± sd of six plants of each poplar line and each treatment. Significant differences at P < 0.05 between treatments are indicated with different indices.