Fig. 5.
The hypocotyl growth response to nitrate requires auxin, SAURS, and SAUR-regulated PP2C.Ds. Seedlings transferred from 0.5 mM to 5.0 mM nitrate 1 h after the beginning of the photoperiod of day 4 are compared to the controls that remained on 0.5 mM nitrate. Hypocotyl growth rate in seedlings of the wild type, auxin-synthesis mutants (A), multiple saur mutants or transgenic SAUR overexpressors (B, OX), multiple pp2c.d mutants (C) or multiple pp2c.d mutants complemented by wild-type PP2C.D2-GFP or PP2C.D2M331K-GFP (D). (E) Model that integrates the results. Data are means ± SE and individual values. Asterisks indicate the significance of the effect of nitrate in Bonferroni tests following significant interaction (int): *P < 0.05; ***P < 0.001; ns, not significant.