Fig. 4

Pollen viability and morphology of the SlAMS-silenced tomato plants. a. The performance of flowers of SlAMS-silenced, −knockouted and -overexpressed plants. b. Pollen grain staining after VIGS-mediated gene silencing of SlAMS. pTRV2-SlAMS transformed; pTRV2 basic vector transformed (negative); Untransformed (WT). Blue-stained pollen grains are non-viable; colorless pollen grains are viable. c. The non-viable pollen grains percentage of SlAMS-silenced, −knockouted and -overexpressed plants and their corresponding wild type plants. **represents significance difference at 0.01 level (P < 0.01). Data are shown as means±SD (n = 3). d. Scanning electron microscope (SEM) images of pollen grains of SlAMS-silenced, −knockouted and overexpressed plants. Untransformed wild type (WT, oval). SlAMS silencing (showing tetragonal and sunken shapes). SlAMS knockout (showing round or shriveled shapes, from CR-T0–5). SlAMS overexpression (showing rhombic and other deformities, from OV-T0–3)