Figure 2.

JA and cytokinin responses in PEG-treated roots. (A) Xylem development of Col-0 roots grown in the indicated conditions for 7 days (cytokinin [CK], 50 nM BAP; JA, 10 μM MeJA; CK/JA, 10 μM MeJA and 50 nM BAP). The red arrows indicate extra xylem. (B) Quantification of the number of xylem cells formed in these roots (n>21). Error bars represent S.E. and asterisks indicate statistically significant differences between the corresponding samples and the control (p < 0.01, Student's t-test). (C) Expression of JA-responsive and cytokinin-responsive genes in the roots grown in the PEG-untreated (grey) and -treated (blue) conditions. Total RNAs were extracted from 8-day-old Col-0 roots grown in PEG-untreated (water potential = −0.25 MPa) and -treated (water potential = −0.70 MPa) conditions. Error bars represent S.D. Scale bar = 20 μm.