Drought survival analysis of variegated lines of Arabidopsis . (a-d) Application of the threshold test. The Fv/Fm measurements of individual (a) Columbia (◇), (b) var1-1 (Δ), (c) var2-2 (□) and (d) alx13 (○) specimens immediately prior to rehydration are shown. Filled symbols represent controls; empty symbols represent plants that failed to evidence signs of recovery within 3 days of rehydration. The 33% threshold for each line is shown as a dotted line. For control populations, n = 7 for each line; for drought-treated populations, n = 16 for each line. For clarity, only measurements from 4 control plants are shown. (e) Comparison of drought survival times of variegated lines. Error bars indicate standard deviation. Pairwise t-tests were performed against survival times of wild-type Columbia plants, yielding p-values as shown; n.s. = not significant. Data shown are the combined results of two separate experiments.