Fig. 3

Analysis of drought-induced related phytohormone and expression levels of critical genes response to drought physiology. (A) Concentration of phytohormone (ABA, GA, IAA and SA) in leaves. (B) Heat map of transcriptional fold changes of genes involved in ABA signal pathway and PIPs relative to reference gene. The four water conditions (well-watered condition (WW), partial-root zone drought in horizontal (H-PRD) and vertical (V-PRD) direction, and full root-zone drought (FRD)) are combined with nitrate (NN) or ammonium (AN) treatment. Means ± SE are indicated by the columns and the bars above columns (n = 4). Statistically different values (P < 0.05) based on the multiple comparisons (Fisher’s LSD test) in ANOVA are indicated by different letters above the bars. The results of two-way ANOVA (water effect, nitrogen effect, and interaction effect) are listed as: *P < 0.05; **P < 0.01; ns, not significant