Pollen-specific flavonol accumulation contributes to male fertility by ROS scavenging in Arabidopsis. (A) Images of CM-H2DCFDA-stained pollen grains of wild-type (Col-0), myb21, myb21myb24myb57, myb11myb12myb111, and chs with and without drought treatment. Bars=50 μm. (B) Quantification of DCF fluorescence in pollen grains of the wild type and the flavonoid biosynthesis mutants. Different letters above the bars indicate significant differences between groups (P<0.05; ANOVA with Fisher’s LSD test). (C) Main shoot bearing siliques of wild-type, myb21, myb21myb24myb57, myb11myb12myb111, and chs plants with and without drought treatment. (D) Percentage of siliques with seeds in wild-type, myb21, myb21myb24myb57, myb11myb12myb111, and chs plants with and without drought treatment. Error bars indicate the SD of three biological replicates. Different letters above the bars indicate significant differences between groups (P<0.05; ANOVA with Fisher’s LSD test).