Morphology of flowers and pollen from of transformants. (A) Over expression of pkv results in reduced flower size (XS) as compared to control (X) and XAS. (B) Light microscopy of acetocarmine-stained pollen from control (X), XS, and XAS anthers. The arrow in XS points to defective pollen grains which appear white and collapsed in the picture and are adjacent to a viable pollen grain which appears red in the picture. Bar = 20 μm.