Fig. 2.

GhMKK16 positively regulates drought tolerance in cotton. (A) Relative expression levels of GhMKK16 in GhMKK16 transgenic plants. OE7 and OE8 are overexpression lines, R8 and R25 are RNAi lines. (B) Phenotypes of transgenic and WT plants under drought stress treatments. Plants at trefoil stage in soil were exposed to drought stress for two weeks. Bars = 3 cm. (C) Water loss of transgenic and WT plants at room temperature. (D) Scanning electron microscopy images of stomata from the abaxial epidermis of cotton leaves in transgenic and WT plants under normal or drought conditions. Bars in 450X was 50 μm, Bars in 3000X was 5 μm. (E) Relative expression levels of GhABF1 in GhMKK16 transgenic and WT plants under control and drought stress conditions. (F) Relative expression levels of GhABF2 in GhMKK16 transgenic and WT plants under control and drought stress conditions. (G) Relative expression levels of GhNCED3 in GhMKK16 transgenic and WT plants under control and drought stress conditions. Plants in (E, F and G) were incubated with normal or drought stress condition, respectively. Values in (A, C, D, E, F and G) represent means ± SE (n = 3). Different lower-case letters a–e above columns represent significant differences among columns (LSD multiple comparisons, P-value < 0.05).