Fig. 4

Correlation between Fv’/Fm’ and drought survival in drought-tolerant Arabidopsis transgenic lines. (A) Fv’/Fm’ exhibited by Col-0, ATAF1-2ox, and PLATZ1-8ox plants in well-watered conditions. Letters, significant differences (n = 18 plants, three independent experiments, one-way ANOVA and Tukey’s HSD test, P < 0.01). (B) Calibration of the threshold for Col-0 with single Fv’/Fm’ measurements of drought-treated Col-0 individuals before recovery irrigation. Redline, threshold estimated by a GLM; R, point biserial correlation coefficient (n = 30 plants, three independent experiments). (C) Single measurements of drought-treated plants before receiving a recovery irrigation. Redline, threshold estimated by a GLM; R, point biserial correlation coefficient (n = 75 plants, three independent experiments). Legend in C) also applies to B). (D) Col-0, ATAF1-2ox and PLATZ1-8ox plants under a severe drought treatment before (upper) and after (lower) receiving a recovery irrigation. Labels, Fv’/Fm’ values