Table 2 Chlorophyll fluorescence measurements of VC and CAx plants grown in soil. VC and CAx Arabidopsis thaliana plants were cultivated for 6 weeks in soil and watered with half-strength MS medium two times in a week. Minimal chlorophyll (Chl) afluorescence (F o), maximal Chl fluorescence (F m), maximal variable fluorescence (F v), and F v /F m ratio, F v /F o and performance index (PI) whereF v = F mF o (WT- wild type, VC-vector control; CAx3 and CAx5- two different transgenic lines). Each data point is the average of six replicates with standard error, ±SE. Asterisks indicate significant differences determined by t test (*P<0.05, **P<0.001).