Figure 8.

Effect of the manipulation of the endogenous NO level on root gravitropic response. Seedlings were grown vertically for 5 days, then they were transferred to media containing the NO scavenger cPTIO (2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, A,B) or the NO donor SNP (sodium nitroprusside, C,D) and immediately rotated by −135° for 24 h. Representative pictures (A,C) and quantitative analysis of the effect on the gravitropic bending of the wild type (AtCol-0) and mutant (Atcrk5-1) roots (B,D) are shown. Red arrows indicate the direction of the gravity vector. The pictogram at the Figure 8A shows the mode of the determination of the root curvature degree, the red semicircle with arrows indicates the measured angle. Asterisks indicate significant differences at * p < 0.1, ** p < 0.01 and *** p < 0.001 between wild type (AtCol-0) and mutant (Atcrk5-1). Measurements were performed with at least 30 seedlings per each line. Bars indicate standard error. At least two biologically independent experiments were carried out with the similar statistical results.