Figure 1.

ROS is involved in different aspects of plant reproduction. ROS has been shown to regulate female and male gametophyte development, pollen-pistil interaction, pollen tube growth, and pollen tube rupture. Dark blue color indicates superoxide (the same color as NBT staining used for superoxide detection) and brown indicates hydrogen peroxide (the same color as DAB staining used for detection of hydrogen peroxide). mmc, megaspore mother cell; syn, synergid cells; cc, central cell; an, antipodal cells; mp, mature pollen.