MdPRP6 negatively regulates the drought tolerance of apple plants. (a, b) Morphology differences in whole plants (a) and top enlarged view (b) of WT and transgenic apple plants under control and drought conditions. Forty‐five‐day‐old WT and MdPRP6‐Ri plants in the greenhouse were withheld from water for 8 days. The Scale bars in (a) and (b) were 15 cm and 7 cm, respectively. (c–h) Leaf angle (c), relative water content (d), electrolyte leakage (e), net photosynthesis (Pn) (f), Fv/Fm ratio (g), and chlorophyll fluorescence images (h) in WT and MdPRP6‐Ri plants with and without drought treatment. The Scale bar in (h) = 3 cm. Data are shown as the means ± SD. Different letters indicate significant differences according to the one‐way ANOVA followed by Tukey's multiple range test (P < 0.05). WT, wild type, here we used GL‐3 apple (Malus domestic), which was also used as explants in generating transgenic apple plants; MdPRP6‐Ri1/2/3, transgenic apple plants with suppressed expression of MdPRP6 via RNA‐interference.