Root morphology of transgenic plants with altered MdMYB88 and MdMYB124 expression and MsMYB88 and MsMYB124 expression level changes in response to drought. A, Root morphology of nontransgenic plants (GL-3), MdMYB88 or MdMYB124 overexpression plants (OE), and MdMYB88/124 RNAi plants. B, Quantitation of adventitious root length of the plants shown in A. Data are means ± sd (n = 5). One-way ANOVA (Tukey test) was performed, and statistically significant differences are indicated by *P < 0.05. C, Relative expression level of MsMYB88 and MsMYB124 in M. sieversii roots under 20% PEG8000 treatment for 0 or 6 h. Data are means ± sd (n = 3).