Maximum carbon assimilation rates were similar in well watered transgenic plants and their respective null plants, ranging from 15 μmol m−2 s−1 in event SI2 to 22 and 24 μmol m−2 s−1 in events SI4 and SI6, respectively. Water deficit caused a marked decrease in photosynthetic performance of null plants, especially in NSI4 and NSI6, where CO2 assimilation dropped to approximately 50% of the initial value during the water deficit period (Table 3). These plants recovered partially after rewatering, attaining CO2 assimilation rates within 80% of the initial well watered values. In comparison, plants NSI2 showed a stronger decrease of photosynthetic rate during the post-stress period.